Contracting waste management services is one of the most commonly used approaches to delivery of this service and this topic is clearly in the focus of frequent academic research. The goal of this article is to examine trends in the area of solid waste collection and disposal on the municipal level for the Czech Republic and Slovakia in terms of developments over the past 20 years with a focus on the share of inter-municipal cooperation in the delivery of this service. In contrast to Western European countries, which are undergoing re-municipalization, the data obtained for Slovakia and the Czech Republic over 20 years show that municipal solid waste management service is dominated by contracting, which has increased over the examined period. This fact is apparently a reflection of the high rate of fragmentation in municipal structures and the low willingness among municipalities to cooperate. The data obtained also indicate that using external suppliers seems to bring marginal savings that could certainly be substantially larger, potential increases in efficiency via contracting are unequivocally limited by the low quality of contract management. Regarding our core question, we found that the proportion of inter-municipal cooperation between service delivery modes did not significantly increase during the investigated period. The experts interviewed almost uniformly agreed on three critical limits related to the issue of inter-municipal cooperation in MSW management delivery – transaction costs of different types, non-existent regular comparisons of best solutions, and limited motivation to select optimal service delivery modes.