Group O/O+ seats are for newborn babies and infants up to nine to 15-months old (roughly equivalent to 10-13kg in weight).
But picking out the right child seat is anything but child's play.
It's vital that you choose the right seat and use it correctly to make sure that the children you're driving around are as safe as possible.
We're putting some of the best-known seats to the test to see which is best, and take you through the dos and don'ts of child seats.
Before you buy, make sure you read What Car?'s ten rules of child seat buying on the next page.
What Car? WinnersBest overall Britax Cosy Tot PremiumBest money no object Mamas and Papas Primo ViaggioBest mid-price Britax Cosy Tot PremiumBest budget Britax Rock-a-tot Plus SiWhat Car? ranking1 Britax Cosy Tot Premium2 Mamas and Papas Primo Viaggio3 Recaro Young Profi Plus4 Maxi-Cosi CabrioFix5 Graco Logico S6 Bebe Confort Streety7 Bebe Confort Creatis.fix8 Britax Rock-a-tot Plus Si9 Mamas and Papas Pro-Sleep10 Red Castle Sport