More than 200 cyclists were caught riding in the dark without lights during a month-long police crackdown in the Thames Valley.
The enforcement campaign during November saw 220 £30 fixed-penalty notices issued to cyclists stopped in Bucks, Berks and Oxfordshire.
Of those, 140 fines were cancelled because riders showed they had bought lights and 67 payments are pending.
Cyclists have a legal obligation to have lights on their bikes in the dark.
Sgt Paul Thornton, of Thames Valley Police, said: "Anyone caught riding on the road in the dark without lights on will be given a fine.
"We are urging cyclists to get lights and keep themselves safe."