We developed and investigated the causal validity of a picture set specifically designed to assess the implicit autonomy motive (nAutonomy). Studies 1a and 1b describe the empirical selection of a new picture set for the Operant Motive Test. Three further studies examined the causal validity of these pictures. A total of 387 participants (aged 18–79 years) watched film clips with autonomy-relevant or neutral cues (Study 2), completed an online (Study 3a) or laboratory experiment with a baseline measurement (Study 3b) that aroused nAutonomy using the symbolic self-completion paradigm. Using the new pictures, participants who watched a film clip with high nAutonomy cues had higher nAutonomy scores than participants who watched a neutral tutorial film. Furthermore, participants who felt they could not personally express themselves while writing an essay in an online setting had higher nAutonomy scores than participants who felt they could. Finally, interrupting participants while writing an essay resulted in higher nAutonomy scores as compared to baseline. Participants who completed a personal essay had lower nAutonomy scores as compared to baseline, which indicates a satisfied motive. Our results support the causal validity of the new OMT pictures that assess nAutonomy and have wide-ranging implications for future research on nAutonomy. •Provides an empirically robust assessment for the implicit autonomy motive•Expands on an established method for implicit motive assessment•The implicit autonomy motive is aroused by autonomy-related film stimuli.•Writing a self-related essay satisfies the implicit autonomy motive.