This article intends to summarize the findings of studies on the relationship between farmers’ behavioral intentions (BI) and water-conservation behavior (WCB) using the theory of planned behavior (TPB). A systematic review of transcripts obtained from Internet-based searching on reliable scientific databases (e.g., SID, ProQuest, Springer, Science Direct, John Wiley, Sage, Taylor & Francis, Emerald Insight, and Google Scholar) was followed by outfitting data for the Comprehensive Meta-Analysis (CMA) software. Data from a total of 28 studies on WCB were synthesized and analyzed through the CMA procedure. The resulting evidence demonstrates that the total and summarized estimate point (i.e., correlation) for the associations of attitude (ATT), subjective norms (SNs), and perceived behavioral control (PBC) with BI was 0.46, 0.36, and 0.26, respectively (r(t)PBC < r(t) SNs < r(t)ATT → BI). Furthermore, the effect size of the relationship between PBC and WCB was 0.27. The largest effect size pertained to the relationship between BI and WCB (BI → WCB) (r(t)BI = 0.52). The take-home message of the article is that hypothetical statements of the TPB are confirmed, as would be hypothesized. These findings should still be regarded in the field of WCB research; thus, policymakers need to provide solutions and adapt their policy initiatives for water resource management based on these findings. For example, one of the solutions to improve water resource management based on the research results is to examine the views and realities constructed by farmers of water resources and related management styles before carrying out water resource management projects. Identifying the potential capabilities of farmers and their economic and social background to expand water-conservation behavior and the tendency and acceptance of water resource management project to be implemented is also an important requirement in making resource management projects effective. The use of various methods of the individual, group, and collective communication to interact with farmers combined with provision of extension training, as well as mobilizing and organizing farmers to facilitate effective management of water resources are recommended.