Brief interventions for alcohol use disorders have been the focus of considerable research. In this meta-analytic review, we considered studies comparing brief interventions with either control or extended treatment conditions. We calculated the effect sizes for multiple drinking-related outcomes at multiple follow-up points, and took into account the critical distinction between treatment-seeking and non-treatment-seeking samples. Most investigations fell into one of two types: those comparing brief interventions with control conditions in non-treatment-seeking samples (n = 34) and those comparing brief interventions with extended treatment in treatment-seeking samples (n = 20). For studies of the first type, small to medium aggregate effect sizes in favor of brief interventions emerged across different follow-up points. At follow-up after >3–6 months, the effect for brief interventions compared to control conditions was significantly larger when individuals with more severe alcohol problems were excluded. For studies of the second type, the effect sizes were largely not significantly different from zero. This review summarizes additional positive evidence for brief interventions compared to control conditions typically delivered by health-care professionals to non-treatment-seeking samples. The results concur with previous reviews that found little difference between brief and extended treatment conditions. Because the evidence regarding brief interventions comes from different types of investigation with different samples, generalizations should be restricted to the populations, treatment characteristics and contexts represented in those studies.