In Turkey, the high incidences of stomach and oesophageal cancers in East and high incidence of stomach cancer in Northeast regions are remarkable. This study was conducted to identify homecare needs of patients with stomach cancer and their caregivers and the effect of family supportive nursing care on the quality of life of patients and families. The patient and his/her caregiver were assessed with respect to their daily life activities and NANDA was used for the identified nursing diagnoses, NIC for the appropriate interventions and NOC for assessment of the results. This study was conducted in a pre‐test, post‐test, controlled trial model to identify. The sample of the investigation consisted of 72 patients and 72 caregivers. As a data‐collecting instrument, the Quality of Life Scale and Caregiver Quality of Life Index‐Cancer were used. The overall quality of life, global health status and emotional and cognitive functions of the patients in the experimental group improved after the interventions. The overall quality of life and global health status was found to be poorer in the control group patients at post‐test as compared to pre‐test and their physical, role and social functions deteriorated. The caregivers’ quality of life in the control group was affected more negatively with respect to the “Disruption in Daily Life” subscale as compared to pre‐test values.