<p>By engaging local resource users in participatory monitoring, conservation initiatives can improve their public perception, which often strengthens compliance and leads to improved outcomes. However, the linkages among the triad ‘participation’, ‘perception’, and ‘compliance’ have seldom been tested holistically, particularly in marine settings. In eleven Brazilian coastal fishing communities, we tested the effectiveness of this framework over a seven-year period. We started by involving fisheries technicians to monitor fishery landings for two years prior to implementing a participatory monitoring program, which involved trained local residents responsible for recording catches [“participation”]. The participatory monitoring continued for an additional four years. Following this period, fisheries technicians resumed monitoring the fishery landings for an additional year. During the entire program, we queried fishers on how they perceived their quality of life, livelihood and the value of their environment [“perception”]. To gauge the third aspect of the triad [“compliance”], we recorded the fate of the Atlantic goliath grouper (<i>Epinephelus itajara</i>), a critically-endangered fish that is commonly captured alive as bycatch. The participatory monitoring program improved fishers’ perceptions of several attributes and resulted in twice the grouper releases compared to non-resident technician monitoring, while the post-release condition of the groupers also improved. Upon terminating the program, however, releases of Atlantic goliath groupers declined, underscoring the crucial role of sustained participatory monitoring efforts within rural and local communities to ensure effective species conservation. Our study demonstrates linkages from participation and perception to compliance, which boosted conservation outcomes through community-led efforts, as evidenced by increased and healthier endangered grouper releases.</p>