Mean proper motions and parallaxes of 205 open clusters were determined from their member stars found in the Hipparcos (<I/239>) Catalogue. 360 clusters were searched for possible members, excluding nearby clusters with distances D<200pc. Members were selected using ground based information (photometry, radial velocity, proper motion, distance from the cluster centre) and information provided by Hipparcos (proper motion, parallax). Altogether 630 certain and 100 possible members were found. A comparison of the Hipparcos parallaxes with photometric distances of open clusters shows good agreement. The Hipparcos data confirm or reject the membership of several Cepheids in the studied clusters.