Purpose: To assess physical activity and sitting time in workers from varied occupations in a regional urban population of Papua New Guinea (PNG), to identify priorities for worker health in a country experiencing rapid industrial development. Methods: PNG workers from a variety of settings (office [n = 213], blue-collar [n = 131], and retail [n = 52]) completed an interviewer-administered demographic questionnaire, the International Physical Activity Questionnaire—short form (IPAQ) and the Occupational Sitting and Physical Activity Questionnaire (OSPAQ); and had height and weight measured. Comparison of activity and sitting time between occupational groups was undertaken using generalised linear equations, with models including demographic variables and sitting time/physical activity as appropriate. Results: Participants reported median total physical activity (walking, moderate and vigorous PA) of 5025 MET-min/week (80% constituting walking) and over 97% of participants met physical activity guidelines (> 600 MET-min/week). Total sitting time was 7 hours/day (IPAQ) and workers sat for 50% of working hours (OSPAQ). There was no difference between groups total physical activity. Office workers reported more total sitting time and a greater proportion of their work time spent sitting than blue-collar and retail workers reported significantly less total sitting time both p < 0.001) and retail workers reported a greater proportion of their work hours standing than office workers and blue-collar workers. Conclusions: Sitting time in PNG office workers was high, similar to findings from high-income countries, but total physical activity was also high in all groups. As the PNG economy develops and office-based work becomes more prevalent, the challenge will be to minimise sitting time at work whilst maintaining high total physical activity. [ABSTRACT FROM AUTHOR]