Fewer motorists are being caught using their mobile phones in Shropshire, Herefordshire and Worcestershire.
West Mercia Police said 381 people were caught breaking the law last month, a fall of about 15% on the number spotted by police in the previous month.
Tougher penalties have been introduced meaning those caught are fined £60 and receive three points on their licence.
The force said research showed using a phone while driving makes drivers four times more likely to crash.
It welcomed the reduction but said the figures were still too high.