Purpose: To evaluate effectiveness of skin detergent containing synthetic pseudo-ceramide for elderly skin. Method: In February 2005, 16 nursing home residents requiring care and 5 physically independent old-age home residents with a mean age of 82.3 years (range, 65-96 years) were asked to wash with skin detergent containing synthetic pseudo-ceramide for 3 weeks. Frequency of bathing was 2 times/week for nursing home residents and 5-6 times/week for old-age home residents. Before and after using the detergent, moisture and pH of the skin surfaces of the forearm and lower leg were measured, and samples were taken by tape stripping for measurement of sebum and ceramide, and by smear for counting resident bacterial flora. Skin was also photographed for evaluation by a dermatologist. Results: Skin moisture was increased in 11 of 16 nursing home residents and 4 of 5 old-age home residents after use of detergent, although total amount of ceramide per milligram of stratum corneum was decreased in nursing home residents compared to old-age home residents. Skin pH was decreased in 2 residents whose pH prior to detergent use was relatively higher compared to other residents. Number of resident bacteria in subjects displaying higher baseline bacteria counts also tended to decrease. Disappearance of erythema and improvements in dry skin were observed. Discussion: Washing with skin detergent containing synthetic pseudo-ceramide appears useful in retaining skin moisture and acidic pH and in preventing bacterial overgrowth of elderly skin. Since most of Japanese do not have the habit appliying cream or lotion to skin other than face and hands, washing skin with such detergent seems more acceptable in Japan. However, there was a discrepancy between skin condition and total amount of ceramide. Further investigation about the underlying mechanisms is needed.