Background <p>Debriefing is a central component of workplace-based learning in the training of paramedics. While their effects are well documented in simulation and hospital settings, little is known about how debriefing quality, psychological safety, speak-up behaviour, and self-reflection competence are interrelated in real-world emergency medical service settings. The aim of this study was to investigate these relationships and analyze potential differences between paramedic trainees and paramedic field instructors.</p> Methods <p>A cross-sectional observational study was conducted using a standardized online survey tool (July–November 2025). The study aimed to assess psychological safety, speak-up behaviour, perceived debriefing quality, and self-reflection competence. Data were analyzed descriptively and using group-specific Pearson correlations.</p> Results <p>A total of 177 participants, including 61 paramedic field instructors and 116 trainees, were analyzed. Trainees and paramedic field instructors differed significantly with regard to debriefing quality (<i>p</i> &lt; .001) and self-reflection competence (<i>p</i> &lt; .05), while no significant differences were observed for psychological safety or speak-up. Among paramedic field instructors, self-reflection competence correlated strongly with debriefing quality (<i>r</i> = .67; <i>p</i> &lt; .001). Among trainees, the strongest correlation was found between psychological safety and debriefing quality (<i>r</i> = .61; <i>p</i> &lt; .001). Psychological safety was significantly associated with utilization of speak-up in both groups.</p> Conclusions <p>Debriefing should not be considered merely as retrospective discussions, but rather as learning environments that are intentionally designed. The findings suggest that debriefing quality is closely associated with reflective facilitation and a psychologically safe environment, particularly for trainees. The training of on-the-job instructors should therefore specifically address, in addition to methodological facilitation skills, the design of interactions that promote reflection and foster a sense of safety, in order to sustainably improve learning, speak-up culture, and team communication.</p> Trial registration <p>This study is registered in „Deutsches Register Klinischer Studien“ (DRKS-ID: DRKS00037257, Registration Date: 03.07.2025).</p>