The number of biomedical sciences PhDs persisting in academic faculty careers has been declining. As one potential influence on trainees' intention to persist, we investigate the development of scientific communication (SC) skills, hypothesizing that attitudes and behaviors regarding scientific writing, speaking, and presenting predict academic research career intention, through science identity. After adapting a social-cognitive career theoretical model of SC to include science identity and mentor practices, we conducted a longitudinal survey of 185 doctoral and postdoctoral fellows. Structural equation modeling was used to examine relationships among SC productivity, SC self-efficacy, SC outcome expectations, mentor practices in SC, science identity, and research career intention. Results confirmed the overall model and revealed additional specific pathways: SC productivity and SC outcome expectations directly predicted career intention; SC productivity and mentor practices predicted science identity through SC self-efficacy. Demographic factors did not predict intention when controlling for SC variables. Findings support a model of SC skill development as a predictor of research career intention (R 2 = .32). The finding that SC language use predicts science identity has important sociolinguistic implications. The key factors in this process are actionable at the trainee, mentor, and institutional levels, suggesting potential for SC interventions to increase career persistence.