Background/Question/Methods Participatory Action Research (PAR) approaches usually bring together researchers and stakeholders in a process that seeks to produce both scientific knowledge, as well as an action process that benefits non-research partners. PAR has been criticized by many scientists for its potential lack of scientific rigor and biases that may result from a researcher's commitment to support PAR partners. On the other hand, PAR supporters claim that this approach results both in better quality research results, as well as a direct contribution to resolving the problems that were investigated. My paper presents a critical review of PAR approaches in agroecology and rural livelihoods, and uses a decade-long PAR case study with coffee farmers in El Salvador to further discuss the challenges and opportunities of the approach. Results/Conclusions The literature and the case study both show that the application of PAR approaches takes more time, but not necessarily more financial resources, than conventional research. In addition, many of the objectives of idealistic PAR conceptualizations are difficult to accomplish in the field. PAR is highly compatible with interdisciplinarity because it takes into account stakeholder's perspectives, which are seldom purely social or ecological. The PAR approach in El Salvador produced both interdisciplinary academic products as well as 'action' outcomes for farmers. These included peer-reviewed publications, university courses, capacity building and support networks for farmers, formation of a second-level farmer cooperative and developing a relationship with progressive coffee buyers in the U.S. and Canada. Accomplishing this required that researchers wear 'multiple hats' and go beyond their regular academic obligations. Challenges to the process were farmer's lack of interest in research, the impact of supporting action objectives on researcher's time and careers, and conflicts with other rural development actors. Although PAR is a promising approach to advance agroecological research and applications, it is not easy to implement and may be in direct conflict with researcher's professional goals. That said, the results of the case study show promise for PAR as an approach to do interdisciplinary research in agroecology and rural livelihoods that can also result in direct benefits to farmers and rural communities.