Nosemosis is on the list B of International Animal Disease Office. Nosema apis was found in Poznań voivodship apiaries. The level of invasion of this parasite was 0-40% of investigated colonies in particular apiaries. According to the Polish programme only 20% of colonies can be N. apis positive in a honeybee breeding apiary. It is suggested that the minimum should be 30% in a reproduction apiary. Such a level could be found in former Czechoslovakia in a honeybee breeding apiary (30-50%). In the author's opinion the invasion level of N. apis - 20% of colonies - is too hard a programme for Polish conditions.