Zero tolerance to tobacco smoking in Dutch cafes and restaurants is being exercised since a ban came into force last July.
A spokesman for the Amsterdam Police has accepted that it is very difficult to understand the rule that allows cannabis smoking while fining tobacco users.
"For logic it is sometimes impossible to explain, even to the Dutch," the Telegraph quoted him as saying.
"The man was not fined for smoking a cannabis joint but for smoking. You can smoke cannabis but not tobacco in coffee shops," he added.
The unnamed 27-year-old man was caught lighting a hand rolled cannabis joint during a routine police check, and fined because officers found tobacco mixed with the soft drug.
He is expected to contest the case in court.