Almost a quarter of children in Bristol are persistently absent from school, according to Ofsted.
Figures published on Thursday revealed 23.5% of students are missing at least 10% of school hours, which experts believe is a legacy of the Covid lockdowns.
James McNeillie, Ofsted's regional director for the South West, said a rise in children experiencing poor mental health was also a factor behind the large number of students regularly missing school.
A spokesperson for Bristol City Council said: "We recognise that improving attendance is a priority for both academic achievement and keeping children safe."