Abstract. The article deals with specific features and main factors of the evolution of left ideologies and transformation of political parties in the post-Soviet space. It is noted that at the turn of the XX–XXI centuries one of the two main vectors in evolution of Marxist ideas and parties of left trend  in the post-Soviet space –socialist and social-democratic – was laid under a strong influence of a neo-revisionist trend gradually taking leading positions   in the European social-democratic thought. Another vector in development of left ideas in the post-Soviet space became an attempt to convert nostalgia for the Soviet Union into electoral successes in the political arena, an attempt to maximize voters support through a strategy of ideological continuity and reliance on the traditional electoral basis. This trend became characteristic of Communist parties which emphasized their  CPSU  ideological  legacy.

It is stressed that left parties in the post-Soviet space experience serious organizational problems. They gradually turn into the so-called catch-all-parties devoid of a clear social and ideological basis. Many of them are only indirectly related to Marxism. Three decades after the collapse of the USSR the left forces have failed to reverse the negative trend for them – that is  their  gradual ousting from the political arena and their marginalization in the political process. Therefore there are clearly insufficient grounds in organizational, ideological and political terms  for a "left turn" in the post-Soviet space.