The diversity and abundance of bumblebees (Bombus Latr.) in eight parks of Warsaw city and the impact of park size (range from 1.9 to 73 ha) as well as other selected characteristics (the percentage of the area covered by tree and the quality of park surroundings) on the bumblebee community were evaluated. In each park, bumblebees were observed along designated paths for 30 minutes. In total, 12 species of bumblebees were recorded, of which four belonged to cuckoo bumblebees (Psithyrus subgenus). We found: B. terrestris (L.), B. lapidarius, (L.), B. pascuorum (Scop.), B. hortorum (L.), B. semenoviellus (Skorikov), B. hypnorum (L.), B. ruderarius (Müller), B. pratorum (L.) and four cuckoo bumblebee species: B. (Ps.) bohemicus (Seidl.), B. (Ps.) campestris (Pz.), B. (Ps.) rupestris (F.), B. (Ps.) vestalis (Fourc.).

The size of parks, percentage of area covered by trees, and characteristics of the areas surrounding the parks were found to be not significant for the diversity and abundance of bumblebees in urban parks. However, our results indicate the importance of the semi-natural areas within the parks for the species diversity.