The paper addresses the problem of professionally-oriented foreign language communicative competence development in the case of non-linguistic students. From the psychological perspective, this competence is viewed as a dynamic integral personal characteristic providing effective interaction in a foreign language in a professional context (Atamanova, 2009). It seems reasonable that students' personal potential (Leont'ev et al., 2007; Bogomaz & Matsuta, 2010) and communicative potential (Bogomaz & Karakulova, 2010; 2011) can contribute to the process under study. Personal potential is responsible for initiating one's intellectual and creative activity and enables to achieve meaningful goals, while communicative potential indicates one's ability to interact effectively in various contexts. The first objective of the study presented was to identify possible relationships between engineering students' personal and communicative potential and their foreign language communicative competence. The study sample (131 university students) was made up of undergraduates (first-year and second-year students) and master's students. A set of questionnaires was used to evaluate the participants' personal and communicative potential, their level of communicative competence being assessed by their English teachers using a 7-point grading scale. Correlation analysis revealed statistically significant in-group correlations between the participants' foreign language communicative competence (p < 0.05) and a number of personal potential parameters (challenge, persistence, orientation to present, ambiguity tolerance and self-worth) and self-understanding in communication as a communicative potential parameter. Furthermore, it was confirmed that foreign language communicative competence is a dynamic characteristic, since there was a statistically significant positive correlation (p < 0.05) between its level and the participants' age. The second objective of the study was to explore experimentally the dynamics of engineering students' foreign language communicative competence development in their professional context. The sample included 24 second-year students of Tomsk State University and their major was technical physics. The educational process was organized based on the program created (Atamanova & Kashirina, 2011) focusing on mini-research as a technique for developing students' professionally-oriented communicative competence in English. The participants' communicative competence was evaluated as follows: at the beginning of the experiment, during the first mini-research project presentation and during the second one. It was shown that the dynamics of the participants' communicative competence development was different in the groups of ambiguity tolerant and intolerant students. These two groups also statistically differed (p < 0.05) in a number of parameters, namely purposefulness, self-organization of activity index, justice, controllability, and selfunderstanding in communication.