BackgroundMore than 50% of Qatari adults are physically inactive. The workplace is an excellent environment to implement cost-effective, efficient behavioural physical activity (PA) interventions to increase PA. This study evaluated whether a pedometer-based walking challenge would increase PA levels amongst hospital workers.MethodsA pedometer-based workplace walking intervention was implemented in April–August 2017. Amongst 800 recruited full-time hospital workers, a cross-sectional sample of 212 workers completed the online questionnaires Quality of Life Questionnaire, International Physical Activity Questionnaire (IPAQ), and Workforce Sitting Questionnaire. A sub-sample of participants (n = 54) wore a pedometer for 3 months. They recorded their daily step count through an online web platform linked to the pedometer. Another cross-sectional sample (n = 194) in the same target population completed online questionnaires at post intervention.ResultsThe IPAQ assessed physical activity at post-intervention was higher compared to pre-intervention. In a sub-sample (n = 54) that provided pedometer data, workers’ step count during intervention was significantly higher (9270) from pre-intervention (7890) (p = 0.048).ConclusionsAlthough self-reported PA was higher post-intervention, the subsample showed objectively assessed physical activity did not exceed the threshold recommended for optimal health. Therefore, encouraging participation and maintaining motivation amongst workers in a work-based PA programme is challenging.