Validation therapy was originated by N. Feil who had questioned the benefit of reality orientation for disoriented old people Validation is a therapy communicating with elderly demented people and is based on an attitude of respect and empathy for them. In validation therapy individuals with dementia are neither forced into orientation nor to change their behavior. The purpose of this study was to explore the effects of validation therapy on Korean dementia sufferers. 29 subjects with dementia and lived in J residential home in Seoul were selected for a nonequivalent, non-synchronized control group design. 14 of them were assigned to the experimental group and 15 to the control group. A program comprising 10 sessions group validation therapy was conducted for 2 weeks in January 1998. The evaluating tools of this study were Clifton Assessment Procedures for the Elderly(Pattie & Gilleard, 1979) and Apparent Emotion Rating Instrument(Snyder etc, 1997). Fisher`s exact x^2-test and t-test were used to analyse the group equivalency and ANCOVA was to test the hypotheses. Analysis of data showed that, following validation therapy, there was a statistically significant difference in behaviour and emotion between the experimental and the control group Social behaviors such as helping others, understanding what was told, being understood, etc were much more increased than functional behaviors like incontinence, getting lost, disordered appearance, etc. Positive emotions-pleasure, interest, and tranquility were much more increased than negative emotion-depression, anxiety, and anger. It has been revealed that most validation techniques were effective for Korean dementia sufferers. Therefore, dementia care givers are recommended to learn how to use validation techniques so that the dementia sufferers may relieve anxiety and maintain dignity. The results of this study suggest that validation therapy is a potentially valuable nursing intervention for people with dementia and warrants further investigation.