Abstract. We study the minimal set of (Lefschetz) periods of the C 1 MorseSmale diffeomorphisms on a non-orientable compact surface without boundary inside its class of homology. In fact our study extends to the C 1 diffeomorphisms on these surfaces having finitely many periodic orbits all of them hyperbolic and with the same action on the homology as the Morse-Smale diffeomorphisms.We mainly have two kind of results. First we completely characterize the minimal sets of periods for the C 1 Morse-Smale diffeomorphisms on non-orientable compact surface without boundary of genus g with 1 ≤ g ≤ 9. But the proof of these results provides an algorithm for characterizing these minimal sets of periods for the C 1 Morse-Smale diffeomorphisms on non-orientable compact surfaces without boundary of arbitrary genus.Second we study what kind of subsets of positive integers can be minimal sets of periods of the C 1 Morse-Smale diffeomorphisms on a non-orientable compact surface without boundary.