BACKGROUND: The Korean National Horticultural Research Institute (KNHRI) supplies many seeds for horticulturus farmers. The seeds of radish (Raphnus sativus acanthiformis) or Chinese cabbage (Brassica campestris pekinensis; cabbage) is one of their major products, and many employees have been exposed to these pollens occupationally. OBJECTIVE: We reviewed the questionnaires for allergic diseases and occupational history. We evaluated the prevalence of the sensitization to radish and cabbage pollens in the workers of KNHRI and analyzed the allergenicity of radish and cabbage pollens. METHOD: Fifty-fuve employees of KNHRI were enrolled in this study. Among them, 12 workers dealed with radish and cabbage pollens directly and were involved in the process of breeding these pollens. The skin prick test with extracts of radish and cabbage pollens and 12 common inhalant allergens were performed. Specific IgEs (sIgE) were detected by ELISA and immunoblotting. Cross-reactivity was determined through inhibition ELISA. RESULT: About 20% of the 55 workers showed positive response to radish and/or cabbage pollens. sixty-six percent of the direct exposed workers and 6.9% of the non-exposed workers showed positive responses to radish and/or cabbage pollens. Prevalence of allergic diseases was 56.4% in the workers. sIgE to radish and cabbage pollens were detected in 50% of exposed workers by ELISA. IgE immunoblotting showed sIgE binding at 24kD, 19kD, 9kD, and 8kD proteins of radish. sIgE also bound to 49kD, 36kD, 24kD, 19kD, and 9kD. Strong cross-allergenecity was found between radish and cabbage extracts on ELISA inhibition. CONCLUSION: Radish and cabbage pollens are significant occupational allergens to the exposed workers of KNHRI. Personal protective devices should be required for these workers.