Since 1989 candidates in Belgian elections have to declare their campaign expenses, but there is a widespread doubt as to the validity of the declared expenses as an indicator of the real cost of the campaign. After the 2000 local elections, data were collected concerning the campaign expenses of 2762 candidates spread over 134 municipalities in the Flemish region of Belgium. An analysis relating the declared expenses to a number of predictor variables reveals a sensible and systematic pattern, which can be interpreted as an indirect indication of their validity. There is a limit on spending, but the research shows that, on average, the candidates only spend 25% of what they are allowed to. Controlling for a number of relevant background variables, the campaign expenditures were found to have a substantial effect on the preference votes for the candidates.