Bumblebee venom allergies, though uncommon among the broad public, pose a significant risk in plant industry and scientific occupation. Since a significant IgE cross-reactivity between bumblebee and honeybee venom has been described in several cases and bumblebee venom for immunotherapy has been available only from a few suppliers, SIT with honeybee venom was frequently used for bumblebee venom allergic patients in the past. We present the case of occupational bumblebee allergy in a biologist who developed anaphylactic reactions with subsequent stings. He was lacking cross-reactivity to honeybee venom, therefore we initiated immunotherapy with bumblebee venom extract. Two months after reaching the maintenance dose of 80 microg, the efficacy of the treatment was demonstrated by sting challenge.