Four people were taken to the Royal Sussex County Hospital in Brighton on Boxing Day (Dec 26), following a collision in Hailsham.
It happened at around 1.45pm between a silver Vauxhall Astra travelling north in Ersham Road and a black Ford Focus travelling south.
A man and a woman from the Astra and two women from the Focus were treated for their injuries in hospital, although none were deemed to be life-threatening.
PC Stuart Kenway of the Surrey and Sussex Road Policing Unit said:
"If you saw what happened, please contact us via collision.appeal@sussex.pnn.police.uk, or by calling 101, quoting serial 435 of 26/12."