Transcript for Jimmy Kimmel on Oscars hosting: 'It's fun when things go wrong.'
Kimmel is already known for gags. You are not the father! Reporter: But the 50-year-old brooklyn-born comic has distinguished himself in the past year for his political activism. My family has health insurance. We don't have to worry about this. Reporter: Most recently an emotional response to the 17 killed in parkland, Florida. Children are being murdered. Reporter: What do you say to your critics to say who are you to speak out on these issues? I'm an American, that's who I am. People are going with this line of reasoning where they say people in show business shouldn't speak out about politics, and yet they elected Donald Trump the president of the United States. So I think that argument is pretty well jumped out the window. Tweets a typo at midnight then wakes up and claims it was a secret message. Reporter: Do you think there maybe have been times when you pushed the envelope too far and become too political? No, I don't. Reporter: You don't regret anything you've said? No, I don't. I am still doing a comedy show and need to entertain my audience. But I think we've matured enough to the point where we can accept late night talk show hosts speaking about a serious subject and I think that it's almost necessary now. Reporter: This new outspoken Kimmel will host the oscars this Sunday, his second in a row. For Kimmel, the show presents a golden opportunity. So much has happened since you hosted last year. We have the times up movement, me too movement. Everything going on with gun control and politics. Are you nervous at all that you're going to strike the right tone? Yeah, I do worry about that. Because I have a tendency to not strike the right tone in my life. Reporter: But this is a really tough year to try to be a comedian in light of everything that's going on. Sometimes it actually goes the other way. Sometimes people are so tense and worried about that kind of stuff and serious that it actually makes people -- it's almost like in a way laughing at a funeral. Sometimes that will play to your advantage. Reporter: How will you know if you've gone too far? I'm sure the internet will tell me. Reporter: You probably saw there's a "Usa today" poll that was released recently that said 94% of women in Hollywood have been harassed or assaulted. That's your audience right there. Yeah. Reporter: How do you address it? Here's the thing. This show is not about reliving people's sexual assaults. It's an awards show for people who have been dreaming about maybe winning an Oscar for their whole lives. And the last thing I want to do is ruin that for someone who is, you know, nominated for best leading actress or best supporting or best director or cinematography or whatever by making it unpleasant. That's not what I want to do. Reporter: Meryl Streep has phoned it in for more than 50 films. The jokes were flowing during Kimmel's Oscar debut last year with many of his signature stunts. Hello there. Reporter: You might remember the awe-struck tour group walking into Dolby theater. Let me give you a little tour. Reporter: Or the candy parachutes falling from the ceiling. Who could forget that infamous best picture snafu. There's a mistake. "Moonlight" you guys won best picture. I'm still not clear on how the wrong envelope got into Warren beatty's hands. I'll be honest, it would be funny if it happened again. Reporter: Are there any safeguards in place to make sure what happened last year doesn't happen again? I think that the biggest safeguard there is is that this company, price Waterhouse coopers, will literally have to go out of business if they do it a second time. So I think they're going to be very, very careful. Reporter: It's been a whirlwind year for the late night talk show host. His son Billy was born with a congenital heart defect and had open heart surgery just days after birth. Jimmy sharing his family's struggle on the show. Billy was born with -- a heart disease. He had another open heart surgery last year. And we're having his lips done when he turns 6. Reporter: Is he okay with that? He asked for it. It was his decision. We don't force these things on our children. Reporter: I did not see that one coming. He's having another open heart surgery around when she's 6 years old. Reporter: You love to shock me. You just shocked me with that. It helps me get through the serious moments. Reporter: But he's a happy boy. He's a very happy boy. It's crazy. He has no idea what happened. Sometimes I look at him and think you don't care what we went through, do you? You just want oatmeal. Reporter: And prepping for Sunday is a family affair with Kimmel working closely with his wife Molly who is the head writer for "Jimmy Kimmel live" and co-head writer for the oscars. I know what to say in any scenario this is a great lesson. If you have the final say and the person who is saying it doesn't you probably have a problem. Reporter: Do you have any anxiety going into this year? I want to make sure everything's right and the jokes can be as good as they possibly can be. I've now whittled it down to 500 joke. Hopefully by the end of next week I'll have that whittled down to 100 jokes. 30, I guess. Reporter: You go from about 500 to 30. No, I go from thousands to 30. Reporter: Oh, my goodness gracious. Jokes aside, it's actually Kimmel's quest for imperfection that he thinks make any show a success. As long as nobody's getting crushed, I think it's fun when things go wrong. I knew I would screw this show up. I really did. The worst thing that could happen is everything goes perfectly. Reporter: You don't want things to go perfectly. No. Reporter: You secretly want the wheels to fall off a little bit. At least one wheel. Two wheels you're grounded but one you can repair. Reporter: You kind of thrive on the chaos. I like it when there's a little -- kind of stay on your toes. Reporter: Nor "Nightline" I'm Paula Faris in Los Angeles.
This transcript has been automatically generated and may not be 100% accurate.