Afghanistan pulled off a two-wicket victory against Bangladesh on Wednesday to level the series, after losing a thrilling opening match days earlier by seven runs.
Mosharraf, who played the last of his three three ODIs back in 2008, replaces pace bowler Rubel Hossain for the decider on Saturday in Dhaka.
"We have seen Afghanistan were struggling to play spin bowling in the first two matches. So we've decided to include Mosharraf for the third match," said chief selector Minhajul Abedin.
Afghanistan have proved tenacious opponents against the more fancied Bangladesh.
The Afghanistan series was hastily arranged to give Bangladesh some cricket ahead of a more serious engagement against England in October.