A set D of vertices in a graph G is a k-fair dominating set if every vertex not in D is adjacent to exactly k vertices in D. The weighted k-fair domination number wfd k (G) of a vertex-weighted graph G is the minimum weight w(D) among all k-fair dominating sets D. In addition to the weighted k-fair domination number, some auxiliary parameters are defined. It is shown that for a cactus graph, the weighted k-fair domination number and auxiliary parameters can be calculated in linear time.