Two new species of flatworms, Pleioplana bosphorensis sp. nov. and Pleioplana Okusi sp. nov., Acotylea, Polycladida, are described from the shallow rocky shores of the Turkish Straits System, northwestern Turkey. Both species are characterized by a prostatic vesicle of atomata-type, stylet and Lang's vesicle. Pleioplana bosphorensis possesses a body of fleshy consistency and without tentacles, with spermiducal bulbs; elongated seminal vesicle and rounded prostatic vesicle with four tubular chambers and a conical, strong, large and straight stylet. Pleioplana Okusi has a translucent body, tentacular knobs, large seminal vesicle, elongated prostatic vesicle with six tubular chambers, and a long slender slightly curved stylet.