The objective of this retrospective cohort was to describe the association of ethnicity, socioeconomic and family key worker status with incidence and severity of Paediatric Inflammatory Multisystem Syndrome Temporally associated with SARS-CoV-2 (PIMS-TS). This study was carried out in two pediatric hospitals, and 70 children with PIMS-TS admitted 14 February 2020-2 June 2020 participated. It was found a significantly higher incidence in children from black (25.0 cases per 100 000 population), Asian (6.4/100 000) and other (17.8/100 000) ethnic groups, compared with 1.6/100 000 in white ethnic groups (ORs 15.7, 4.0 and 11.2, respectively). Incidence was higher in the three most deprived quintiles compared with the least deprived quintile (eg, 8.1/100 000 in quintile 1 vs 1.6/100 000 in quintile 5, OR 5.2). Proportions of families with key workers (50%) exceeded catchment proportions. Admission length of stay was 38% longer in children from black ethnic groups than white (95% CI 4% to 82%; median 8 days vs 6 days). 9/10 children requiring ventilation were from black ethnic groups. From the previous results they concluded that children in ethnic minority groups, living in more deprived areas and in key worker families are over-represented; children in black ethnic groups had longer admissions; and that ethnicity may be associated with ventilation requirement.