This paper deals with the potential effects on the profitability of Canary Islands’ farms due to the Special National Insurance System for Agricultural Workers Reform which was put in place in 2009 by the Spanish Government Ministry of Labour and Immigration. The effect on the employers’ National Insurance contributions per working day is analysed. Based on this analysis, the impact on costs and benefits in several farms which cultivate bananas, tomatoes or flowers is evaluated. According to the results, it is concluded that these farms cannot afford the costs’ increase derived from the reform if profitability per product unit or per surface should be maintained. On the other hand, the effect of changes in the contribution basis is softened to a great extent by the application of compensatory deductions, which are likely to disappear on the long term.