Background Smartphones can optimize the opportunities for interactions between nursing home residents and their families. However, the effectiveness of smartphone-based videoconferencing programs in enhancing emotional status and quality of life has not been explored. The purpose of this study was to evaluate of the effect of a smartphone-based videoconferencing program on nursing home residents’ feelings of loneliness, depressive symptoms and quality of life. Methods This study used a quasi-experimental research design. Older residents from seven nursing homes in Taiwan participated in this study. Nursing homes (NH) were randomly selected as sites for either the intervention group (5 NH) or the control group (2 NH); NH residents who met the inclusion criteria were invited to participate. The intervention group was comprised of 32 participants; the control group was comprised of 30 participants. The intervention group interacted with their family members once a week for 6 months using a smartphone and a “LINE” application (app). Data were collected with self-report instruments: subjective feelings of loneliness, using the University of California Los Angeles Loneliness Scale; depressive symptoms, using the Geriatric Depression Scale; and quality of life using the SF-36. Data were collected at four time points (baseline, and at 1-month, 3-months and 6-months from baseline). Data were analysed using the generalized estimating equation approach. Results After the intervention, as compared to those in the control group, participants in interventional group had significant decreases in baseline loneliness scores at 1 months (β = − 3.41, p < 0.001), 3 months (β = − 5.96, p < 0.001), and 6 months (β = − 7.50, p < 0.001), and improvements in physical role (β = 36.49, p = 0.01), vitality (β = 13.11, p < 0.001) and pain scores (β = 16.71, p = 0.01) at 6 months. However, changes in mean depression scores did not significantly differ between groups. Conclusions Smartphone-based videoconferencing effectively improved residents’ feelings of loneliness, and physiological health, vitality and pain, but not depressive symptoms. Future investigations might evaluate the effectiveness of other media-based technologies in nursing homes as well as their effectiveness within and between different age cohorts.