This study was carried out to assess the effects of reminiscence therapy that was supported with internet-based videos on the cognitive condition and apathy levels of older people with mild dementia living in nursing homes. This randomized controlled experimental study was conducted between May 15, 2016, and August 25, 2016, in two nursing homes in Adana, Turkey. A total of 32 people participated in this study, 16 individuals were in the intervention group and 16 individuals were in the control group. The data were collected using a Personal Information Form, the Standardized Mini-Mental State Examination (SMMSE) test, and the Apathy Rating Scale (ARS) Self-assessment Form. The individuals in the intervention group received group reminiscence therapy involving internet-based videos for 60 minutes once a week for 3 months. During this period, 25 to 30 minutes of unstructured interviews were carried out with individuals in the control group. The data were analyzed using descriptive statistics, Student t test, the Mann-Whitney U test, and Wilcoxon signed rank test. In this study, a significant difference was found between experimental and control groups' posttest mean scores on the SMMSE test and ARS (P < .01). The experimental group's SMMSE test and ARS posttest mean scores were higher than those of the control group (P < .01). This study found that group reminiscence therapy using internet-based videos improved the cognitive functions and apathy levels of older people with mild dementia of the Alzheimer type. It is recommended that group reminiscence therapy studies with Internet-based videos be conducted in care institutions that are responsible for managing older people with mild dementia of the Alzheimer type.