Objectives: The purpose of this study is to examine the effects of 3 day Forests healing programs for cognitive improvement, which consists of helpful contents of Korean medicine. Methods: This study examined the effects of forests healing for mild cognitive impairment patients, who visited a Korean medicine hospital neuropsychiatry clinic for outpatients. The Forests healing programs for cognitive improvement was run with 24 participants, in which 9 of them quit in the middle of the program, so excluded in data analysis. The Forests healing programs for cognitive improvement was consisted of 3 day helpful Korean medicine contents. The primary outcome measurement was a Computerized Neurocognitive Test (CNT), which measured the cognitive functions with computer programs. Results: The results of this study showed that CNT scores were not significantly changed after 3 day forests healing. General psychological states, including depression, anxiety, and anger, were also checked. Among them, depressive mood significantly improved. Quality of life (QOL) was also enhanced after 3 day program. These results indicate that the 3 day Forests healing programs for cognitive improvement was effective for depressive mood and QOL of mild cognitive impairment patients, but not enough for cognitive functions directly. Conclusions: The 3 day Forests healing programs for cognitive improvement were shown to be an effective intervention in improving some aspects of mild cognitive impairment patients, including depressive mood, and QOL. We suggest that repeated participation of this program can enhance cognitive function of mild cognitive impairment patients.