In this first contribution on Somalian marine microturbellarians, a detailed description of three new species belonging to the family Polycystididae is given. Very few data are available on representatives of this family from the Indo-Pacific area. The available data are from the American Pacific coasts (Marcus, 1954a; Schockaert & Karling, 1970) and from the Antarctic (Karling, 1952). Karling (1952) described the first Polycystidid, Koinocystella inermis, with a copulatory organ of the conjuncta type; Schockaert & Karling (1970) proposed a new subfamily Duplacrorhynchinae to contain the three new species they described. The Somalian samples collected by the author contained three new species with a remarkable anatomy that deviates from the original Polycystidid schema. They are described below as Djeziraia pardiin.g. n.sp.,Hawadlia papii n.g. n.sp. and Phonorhynchoides somaliensis n. sp.