The purpose of this investigation was to develop the STEM Active Listening Skills Assessment (STEM-ALSA), a conceptually grounded instrument designed to measure four components of active listening, a key element of communication in an academic setting. The STEM-ALSA is comprised of three unique scales that measure a person's knowledge (12 items), ability to apply (25 items), and self-efficacy (5 items) with respect to active listening. Two pilot studies were conducted with N = 99 upper level undergraduate students enrolled in STEM disciplines to develop and evaluate the instrument. Results of an exploratory factor analysis identified both a unidimensional factor structure for each of the three scales and total scores with adequate internal consistency reliability estimates. The STEM-ALSA provides a mechanism for measuring active listening skills among students in STEM.