He captioned the snap, "Young Billy is six months old today. He is healthy and happy and we are all very grateful for your prayers, good wishes, thoughts and support of @ChildrensLA and children's hospitals in your area. (sic)"
In the photo, Kimmel's son looked happy, showing the camera his toothless smile as he laid back in a stroller.
For the unversed, the 'Jimmy Kimmel Live' host and his wife Molly McNearney welcomed their second child into the world six months ago, and were devastated to learn he had to undergo a life-saving heart surgery after doctors discovered he had a congenital heart defect.
The little guy seems to be doing well. Just last month, the then-5-month old attended his first Hollywood bash with his parents and his three-year-old sister Jane.
Kimmel first talked about his son's health scare in May.
He had said that just hours after his son's birth doctors noticed that his baby boy was born with a heart disease. (ANI)