Dutch municipalities have the right to decide on Sunday shop opening hours since 1996. Despite positive effects on economic growth and employment, many municipalities restrict Sunday trading in one way or another. Based on 2003 data we show that especially religious and political afilliation, regional differences and the size of the municipalities explain the variation between municipalities. The number and size of shops and household characteristics are significant although their inﬂuence seems to be smaller. There is less evidence that excessive competition with neighbouring municipalities induces shop opening on Sundays, although cross-border shopping seems to play a role. Population density has no effect.Sunday opening, economic regulation, probit estimation.