(BBC) Half of outlets rated as zero by the Food Standards Agency in Manchester, Bristol and London appear on the app.
A consumer rights campaigner has called for Just Eat to display the hygiene score alongside each entry. Just Eat said it took the issue "very seriously" and will trial the ratings on its Northern Ireland listings.
The BBC investigation found:
20 out of the 31 takeaways rated zero in Birmingham are on Just Eat
Nine of the 13 takeaways rated zero in Liverpool are listed there
In Manchester, Bristol and London, half of the takeaways with a rating of zero are on the platform
Local authorities are responsible for inspecting restaurants and takeaways.
In England, Wales and Northern Ireland outlets are given a food hygiene rating ranging from zero, for "in need of urgent improvement", to five, for "food hygiene is very good".