New car registrations during the month rose 16.1% when compared with a year ago, the Society of Motor Manufacturers and Traders (SMMT) said.
British buyers snapped up 208,976 new cars in April, almost 18,000 more than the previous record of 191,276 new cars sold in a month.
April was the nineteenth consecutive month when the UK car market expanded, SMMT said.
"Although the current rate of growth cannot last forever, with such a strong start to the year, 2002 looks set to be one of the best-performing on record," said SMMT chief executive Christopher Macgowan.
Private buyers
More than half the new cars sold in April were bought by private buyers, the SMMT said.
"Private buyers continue to drive the new car market to record lengths for 2002 as registrations soared 24.5% in April to 108,126 units," said the Retail Motor Industry Federation's franchised dealer director, Alan Pulham.
"With a growing number of new models entering the market, consumer demand is likely to remain high for the remainder of the year."
Diesel boosted
Company car sales were affected by recent tax changes which favour diesel engines.
The sales of diesel cars rose 60.5% in April to gain a 23.2% share of the market, up from a 16.8% market share a year ago, SMMT said.
The raised standards of diesel cars relative to petrol cars also fuelled the shift.