Background and Objectives: Caring for a person with dementia places a significant burden upon informal caregivers and leads to decreased psychological and physical health, which is why dementia caregiver interventions have been developed. However, empirical evidence for the efficacy of those interventions is inconclusive and the last comprehensive meta-analysis (Pinquart & Sorensen. Helping caregivers of persons with dementia: Which interventions work and how large are their effects? International Psychogeriatrics. 2006;18(4), 577-595.) was published more than 10 years ago. Research Design and Method: This meta-analysis aims to update the meta-analysis conducted by Pinquart and Sorensen. Based on a systematic search in electronic data bases, effects of 282 controlled studies were integrated. The effectiveness of different intervention types and influences of study characteristics were evaluated. Results: Interventions had, on average, a significant, small-to-moderate effect on the improvement of ability/knowledge, subjective well-being, burden, depression, and the caregiver's anxiety as well as symptoms of the care recipient. No mean effect was found in regard to reducing the risk of institutionalization. Most intervention types had an effect on the reduction of burden as well as on other outcomes. Psychoeducation and multicomponent interventions affected most outcomes, whereas the efficacy of other intervention types was domain-specific. Discussion and Implications: There is evidence for the efficacy of dementia caregiver interventions, though due to having predominantly small effect sizes, there is still room for improvement. Interventions should be tailored to the desired outcome. More research on long-term effects, effects on anxiety and institutionalization, efficacy of respite and support interventions, care recipient training, and the intervention process is needed.