BACKGROUND: Laboratory animal workers who are in regular contact with furred animals commonly develop laboratory animal allergy (LAA). LAA is one of the most common occupational allergic diseases. OBJECTIVES: This study was performed to estimate the prevalence of sensitization and symptoms of LAA, and to determine important host factors for the development of LAA. METHOD: Sixteen subjects with laboratory animal workers in one medical research center were enrolled in this study. They responded to a questionnaire about work-related symptoms and underwent allergy skin prick test to common inhalant and laboratory animal allergens. RESULTS: The prevalence of sensitization to laboratory animal allergens was 18.8%, and all sensitized workers were atopic (positive skin reactivity to one or more common inhalant allergens). Prevalence rate of allergy symptoms caused by working with laboratory animals was 31.3%. Positive skin prick responses to dog or cat allergens were highly associated with specific sensitization to laboratory animal allergens, and positive skin responses to laboratory animal allergens were associated with laboratory allergy symptoms. Among sixteen subjects, we found out one case of occupational asthma due to mouse allergy and also reported the case here. CONCLUSION: Some laboratory animal workers showed sensitization to laboratory animal allergens and had allergic symptoms attributed to contact with laboratory animals. Atopy, especially atopy to dogs or cats may be an important host factor for the development of LAA.