Abstract. The classical projective «-spaces (real, complex, and quaternionic) are studied in terms of their self maps, from a homotopy point of view. Self maps of iterated suspensions of these spaces are also considered. The goal in both cases is to classify, up to homology, all such maps. This goal is achieved in the stable case. Some partial results are obtained in the unstable case. The results from both cases are used to compute the genus groups and the stable genus groups of the classical projective spaces. Applications to other spaces are also given.1. Summary. Let P" denote a projective «-space (either real, complex, or quaternionic). This paper deals with the classification, up to homology, of self maps /: P" -» P" and g: 2*P" -* 2*P".Here HkP" denotes the zc-fold suspension of P". We shall assume that k is large with respect to « in order to make the second classification a stable one.It is clear that these two problems are related. Indeed for any space X and self maps /, i = l,...,m, one can use the track addition of maps on 1kX to form a linear combination of /i-fold suspensions nxzkfx + ---+nmzkfm.zkx^zkx.Under what conditions can every self map of ^kX be described, up to homology, in this manner? The following result answers this question for the classical projective spaces. In its statement, two maps are called homologous if they induce the same homomorphism in integral homology. Theorem 1. If k is large with respect to n, then every self map of 2,kP" is homologous to a linear combination of k-fold suspensions, if and only if (i) P" = RP" andn¥=3 or 1, or (u)Pn = CPnforalln,or (iii) P" = HP" and n< 4. □ This theorem is a corollary of some of the results that we obtain in the next two sections. In §2, the unstable classification problem is considered. There the quaternionic case receives special attention. Unfortunately, the classification of self maps