Institutionalized elderly who are frail and dependent are vulnerable to be abused by overwhelmed caregivers especially caregiver psychological abusive behavior is a growing but hidden problem with few evidence-based interventions. The purpose of this study was to examine the effectiveness of an educational support group in alleviating caregiver's psychological abusive behavior, reducing work stress and promoting knowledge of geriatric care-giving among a group of caregivers. A quasi-experimental design using a case control pre-post test approach was conducted. A total of 100 participants completed the study with 50 caregivers in each group. The research instruments included the Caregiver Psychological Elder Abuse Behavior Scale (CPEAB), the Work Stressors Inventory (WSI), and the Knowledge of Gerontology Nursing Scale (KGNS). The results showed that the intervention had significant effects in alleviating caregiver psychological abuse behavior and increasing care-giving knowledge in the experimental group (p = 0.048; 0.018). However, the intervention had no measurable effect on work stress (p = 0.66). Findings have important implications for education and programming for facility administers and long-term care policy makers when planning quality improvement for elderly care.