<p>The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) is widely used in agriculture and frequently detected in aquatic ecosystems, raising concerns about its sublethal impacts on non-target organisms such as zebrafish. This systematic review, followed by a meta-analysis, evaluated the toxicological effects of 2,4-D at different developmental stages of zebrafish (<i>Danio rerio</i>). For this, search terms were applied in the PubMed, WoS, and ScienceDirect databases: “TS (Topic Search)”: (“2,4-D” OR “2-4-dichlorophenoxyacetic acid”) AND (“zebrafish” OR “<i>Danio rerio</i>”), which returned 508 studies, from which 18 were selected for the systematic review and 9 for the meta-analysis. Physiological and behavioral parameters were analyzed, including hatching rate, heart rate, and swimming distance. The results indicated a significant increase in the heart rate of embryos exposed to 2,4-D. In addition, distinct behavioral alterations were observed at different life stages: adults showed increased locomotor activity at lower concentrations, while larvae exhibited a tendency toward reduced swimming distance. For hatching rate, a decreasing trend was observed following exposure to 2,4-D. Meta-regressions indicated that herbicide concentration and life stage were relevant moderating variables, suggesting complex and variable response patterns. Overall, the results show that even acute exposures to 2,4-D can affect critical physiological and behavioral processes in <i>Danio rerio</i>, particularly during early life stages, reinforcing the need for long-term exposure studies.</p>