Fifty white laboratory mice were planted in a microbiotope in which adiaspiromycosis has been detected in 52 Microtus arvalis during the last 10 years. Four of the white mice became infected with adiaspiromycosis. Serological tests revealed the infection in two mice exposed for 3 months. After 4 months' exposure, another two mice were found to be infected and the positive serological results were confirmed by microscopical examination which revealed adiaspores in their lungs. The infection was thus detected by serological methods sooner than by microscopical examination.