MD says on 4/Aug/11
Yeah, he's never looked 5'10", too me. Pretty great proportions, and all, but 5'10" he is not.

Mr. R says on 3/Aug/11
Slattery is a weak 5-9.

Tom says on 2/Aug/11
Absolutely great actor, does not look a full 5´10", maybe 5´9" - 5`9.5"?

Dman says on 17/Dec/10
In episode 3 of season 1, there is a scene where Hamm and Slattery are about to enter the office of the company primary owner who doesn't wear shoes in the office. So before entering they both take their shoes off, and Hamm's character gives a surprising look at Slattery;s character becasue while in shoes he is about an inch shorter without them he is 2.5-3 inches shorter. Kind of an inside joke on the show I guess. So 5-9.5 seems about right.