Background Many healthcare workers do not seek help, despite their enormous stress and greater risk for anxiety, depression and post-traumatic stress disorder (PTSD). Aims This study screened for psychopathology and evaluated the efficacy of a brief, social contact-based video intervention in increasing treatment-seeking intentions among healthcare workers (trial registration: NCT04497415). We anticipated finding high rates of psychopathology and greater treatment-seeking intentions post-intervention. Method Healthcare workers (n = 350) were randomised to (a) a brief video-based intervention at day 1, coupled with a booster video at day 14; (b) the video at day 1 only; or (c) a non-intervention control. In the 3 min video, a female nurse described difficulty coping with stress, her anxieties and depression, barriers to care and how therapy helped her. Assessments were conducted pre- and post-intervention and at 14- and 30-day follow-ups. Results Of the 350 healthcare workers, 281 (80%) reported probable anxiety, depression and/or PTSD. Participants were principally nurses (n = 237; 68%), physicians (n = 52; 15%) and emergency medical technicians (n = 30; 9%). The brief video-based intervention yielded greater increases in treatment-seeking intentions than the control condition, particularly among participants in the repeat-video group. Exploratory analysis revealed that in both video groups, we found greater effect among nurses than non-nurses. Conclusions A brief video-based intervention increased treatment-seeking intention, possibly through identification and emotional engagement with the video protagonist. A booster video magnified that effect. This easily disseminated intervention could increase the likelihood of seeking care and offer employers a proactive approach to encourage employees to search for help if needed.