The classification of engineering skills as scarce, in addition to imperatives to attract women to the field of engineering, allows universities the opportunity to develop interventions and programmes to attract, retain, and develop engineering students to become both successful students and successful, practising engineers. The research in this article focuses on the development of a new instrument, a questionnaire named the Self-Efficacy Instrument for Engineering Students (SEIES). It explores the self-efficacy, motivation, and confidence of engineering students at a university in a developing country, as a means to develop and retain them. SEIES was developed, based on nine sub-constructs, namely: maths self-efficacy, learning, problem-solving, coping, inclusion, organisational culture, and teamwork and role expectations. The data obtained from SEIES could also create a greater understanding of the academic motivational drivers and the confidence that engineering students display. It is anticipated that the application of such a research instrument in a longitudinal study would provide a variety of benefits to individual students, the academic faculty, higher education institutions, as well as the industry they serve. This understanding could improve student retention, growth, and development, address gender disparities, contribute to positive university experiences, and reduce the participation barriers for all engineering students. The SEIES data could also provide important information for developing co-curricular interventions, in addition to curriculum design, as well as classroom practice and student interactions.