The review summarises chemical compounds found in exocrine glands of different castes of bumblebees. The sex pheromone of queens, queen pheromones, defence substances, trail pheromones, dominant signals of workers, marks of a food source, and male's marking pheromones are described. Attention is paid especially to the constituents of labial gland secretions of males. An overview is given of the chemistry of 32 species of bumblebees (genus Bombus) and 10 species of cockoo bumblebees (genus Psithyrus), occuring in Europe and America. Similarities and differences in the chemical composition of secretions of related species within subgenera are discussed.