This study aimed to develop and examine the effects of a socially oriented gratitude intervention (SOGI) on secondary students' gratitude level and interpersonal relationships. To these ends, we used a quasi-experimental research design: The experimental group (n = 46) participated in the two-week intervention during a class subject focusing on character and citizenship education (CCE) while the wait-list control group (n = 57) went on with regular CCE activities. All participants completed a questionnaire a week before and a month after the implementation of the SOGI and control activities. The changes in relatedness scores were statistically significant in relation to parents and peers, but not in relation to teachers. In particular, the experimental group generally maintained the quality of their relationship with their parents and peers while the control group reported a decline in these relationship domains. The change in gratitude levels did not differ significantly between the experimental group and control group, but the effect size associated with the mean gratitude change of the experimental group was found to be larger than that of the control group and comparable to what is commonly reported in other published gratitude intervention studies. The students' feedback reveals the social, cognitive and affective benefits of the SOGI.