In this paper we study fuzzy Γ-ideals and prime, semiprime fuzzy Γideals of a Γ-AG-groupoid S. We prove that, if S is a Γ-AG-groupoid with left identity, then every fuzzy Γ-ideal of S is idempotent if and only if every fuzzy Γ-ideal of S is semiprime. We also show that, if S is a Γ-AG-groupoid with left identity e, then every fuzzy Γ-ideal of S is prime if and only if every fuzzy Γ-ideal of S is idempotent and the set of fuzzy Γ-ideals of S is totally ordered by inclusion.