The twofold purpose of this study is to identify engineering students' perceptions of a problem-based learning environment and to analyse the influence of their personal "situation," general "interest" in engineering and "ability" to succeed on their perception, after they were exposed to PBL for the first time. Based on an adjusted version of the problem-based learning environment inventory [Senocak, E. 2009. "Development of an Instrument for Assessing Undergraduate Science Students' Perceptions: The Problem-based Learning Environment Inventory." "Journal of Science Education Technology" 18 (6): 560-569], data regarding students' perception were collected through a questionnaire survey and analysed by applying exploratory factor analysis and structural equation modelling. The analysis revealed a three-factorial PBL environment consisting of learning "facilitator support," "student responsibility" and "project quality," with strong influences of students' personal "situation" on "project quality," "interest" on the learning "facilitator support" and "ability" to succeed on "students' responsibility." Supporting students' general "interest" in engineering seems to improve their perception of the learning "facilitator support" and ensuring students' "ability" to succeed in a PBL environment seems to increase students' awareness of their own responsibility.