Abstract Background Health- and economic-related worries during the COVID-19 pandemic contributed to worsening of mental health, particularly affecting migrants in vulnerable situations. However, this differential impact was only clear some months into the pandemic, and there is little evidence about any differences in health and economic worries between migrants and non-migrants as the pandemic developed. To close this knowledge gap, we assessed the changes in COVID-19-related worries reported by migrants compared to non-migrants in Norway throughout the pandemic. Methods Our study analyzed data from three time points (April-20, January-21, March-22) for 25,305 participants of the Bergen in Change study, including 509 (2%) migrants from Asia, Africa, or Latin America (LATAM), and 1250 (5%) migrants from other regions. Worries were assessed using questions on COVID-19 infection fear, job security, and economic stability. Analysis methods included descriptive analysis, chi-squared, Sankey plots, and logistic regression, adjusting for age, gender, education, and type of work. Results Migrants from Asia, Africa and LATAM reported health worries more often than non-migrants [OR (95%CI) 1.9 (1.3-2.8)] without clear changes over time, 0.9 (0.7-1.3). Migrants from Asia, Africa, and LATAM, as well as from other regions, also reported economic worries significantly more often than non-migrants [3.1 (2.5-3.9) and 2.1 (1.8-2.4) respectively] at baseline. Each additional year into the pandemic increased the odds of economic worries by a factor of 1.3 (1.0-1.6) for migrants from Asia, Africa, and LATAM compared to non-migrants. The odds ratio for migrants from other regions over time was stable, 1.0 (0.9-1.1). Conclusions Migrants, especially those from Asia, Africa, and LATAM, reported more pandemic- related worries than non-migrants, and this persisted over time. Identifying and understanding these worries could guide preventive measures to enhance mental health in migrant population. Key messages • Throughout the pandemic, migrants reported more COVID-19-related worries than non-migrants, a trend that persisted over time and was greater among migrants from Asia, Africa, and Latin America. • Identifying the differential impact of COVID-19 on migrants’ groups and understanding the factors involved is essential for guiding healthcare interventions to improve migrant health.