This study tested, with a sample of United Kingdom (UK) trainee clinical psychologists, part of an existing model of factors that influence clinical psychologists' levels of research activity, in which gender identity is hypothesized to influence research self-efficacy and this in turn strength of intention to do research. A sample of 121 trainee clinical psychologists (56 men and 65 women) completed a measure of gender identity, research intention, and a research self-efficacy scale. Results indicated no differences in levels of research intention or research self-efficacy between the biological sexes or according to category-based gender identities (masculine and feminine). However, masculinity as a scale quantity was statistically significantly related to stronger research intention, preference for conducting quantitative research and research self-efficacy. Multiple regression analysis provided evidence that research self-efficacy may mediate between masculinity and strength of research intention. Research self-efficacy was the strongest predictor of intention to do research in the future. Findings have relevance for clinical psychology training as research activity directly impacts upon advances in the discipline of clinical psychology, implementation of research into practice, and evaluation of psychological therapies.