Cross-disciplinary research is advocated as a way of improving understanding of the complexity of environmental problems; cross-disciplinary projects, centres and academic institutes have increased. However, there is confusion over the nature of cross-disciplinary research. Through review of papers defining themselves as cross-disciplinary that aim to address conservation problems, and by standardizing the definition of cross-disciplinary research, it is possible to evaluate the potential research impact on peers and practitioners. When papers were reclassified by authors, those reclassified as transdisciplinary were perceived to have a greater impact on practitioners, and those reclassified as non cross-disciplinary had the greatest impact on colleagues. Having clear definitions for types of cross-disciplinary research would help establish a firm foundation, not only for improving research quality, but also for evaluating research impact. While the number of cross-disciplinary studies is increasing, cross-disciplinary research falls short of integrating disciplinary methods in much depth and does not have much impact on participants outside of academia.