The Rebus author is inviting readers to a free party in a library in the Capital where he penned some of his most famous chilling scenes.
The generous novelist is even laying on free drinks to anyone who joins in the birthday celebrations.
The event next Tuesday will see Mr Rankin talking about his life and work with literary agent Jenny Brown.
He said he specifically chose to hold his party at the Capital's Central Library for its role in providing inspiration for his best-selling series of crime novels.
The books' grizzled detective character John Rebus closes in on the library at the climax of the very first book, Knots and Crosses.
Mr Rankin said: "Rebus was 'born' while I was a student in Edinburgh, during which time I haunted George IV Bridge, and especially its libraries and bookshops. It is no accident that I chose the Central Library for the climax of that first Rebus novel and it is a pleasure to make the return journey to celebrate my 50th birthday."
Complementary drinks will be on offer to those lucky enough to snap up a free ticket. Organisers at the library urged Rankin fans to book their place early.