In this article, we propose a new approach to solve intuitionistic fuzzy assignment problem. Classical assignment problem deals with deterministic cost. In practical situations it is not easy to determine the parameters. The parameters can be modeled to fuzzy or intuitionistic fuzzy parameters. This paper develops an approach based on diagonal optimal algorithm to solve an intuitionistic fuzzy assignment problem. A new ranking procedure based on combined arithmetic mean is used to order the intuitionistic fuzzy numbers so that Diagonal optimal algorithm [22] can be applied to solve the intuitionistic fuzzy assignment problem. To illustrate the effectiveness of the algorithm numerical examples were given.. © 2018 IAEME Publication.