EN
Paper contains the analysis of theoretical premises of farms' horizontal integration and the factors affecting development of agricultural producers' marketing groups. Nine groups from the area of whole country, representing different legal forms, were included in the survey. The scale of collective sales and co-operation is not too large. Examined groups admitted having profitable economic effects of the collective activity. Further development of these groups depends particularly on achieving budget support on the same level as in European Union countries, on regulation of taxation system, undertaking of group investments and loyal co-operation of the members.