The former James Bond actor was at the Hollywood premiere of his latest film, "The November Man," when he stopped on the red carpet to reminisce about the late Williams.
"It is a deeply sad time for us all on the loss of Robin Williams," Brosnan told reporters. "My first day on set, they said, 'Do you want to meet Robin?' I had never met the man, I was so excited. I was so thrilled to have this job in the company of this great star comedian."
Brosnan described what happened next.
"I walked into the trailer and there was Robin, sitting there in a pair of Ugg boots, hairy legs, shorts, Hawaiian shirt and hairy chest and the head of Mrs. Doubtfire. That's how I met Robin Williams, and that's how I met Mrs. Doubtfire," he said.
"And I had the time of my life. Every day was just sheer magic with the man. His humanity, his grace, his brilliance of heart, mind and soul."
Beside a publicity still from "Mrs. Doubtfire," Brosnan wrote: "Dear Robin…you made me laugh like no other…You bedazzled the world with your brilliant genius. Mrs Doubtfire and you will forever be in my heart, and the memory of you good man, shall remain constant through out my days. It was a joy to work with you on a film that will be passed on from generation to generation. And to your loving family I extend my deepest heartfelt sympathies and prayers. Peace be with you. Pierce."