Paederus dermatitis caused by the contact of staphylinid beetles(Paederus fuscipes) body fluid(pederin) is characterized by linear erythematous vesicopustular lesions. An outbreak of dermatitis occurred at apartments located at the river side after rainy season in summer 1994. Authors surveyed 189 cases(94 males and 95 females) from 103 households reported at the apartment office in Kimcheon on September 1994. The results are as follows; 1. The causative agent of skin diseases was identified as Paederus fuscipes. 2. The attack rate of paederus dermatitis was 52.6% by households, and the residents in the middle floors of the apartments were attacked more frequently than those in other floors. All ages were affected. 3. The skin lesions developed by paederus were distributed on face(38.2%), neck(18.5%), shoulder and trunk(11.0%), arm and leg(10.3%), and back(6.6%). In 21 cases(15.4%), skin lesions were developed in multiple sites. 4. The apartments attacked by paederus was located near the sand and damp soil along the bank of the river. The fodder cultivating farm was located near the upper reaches of river, and a rice field and grape garden in the backyard of the apartment.