The evaluation of municipal solid waste (MSW) services using management systems (ISO 9001, ISO 14001, and OHSAS 18001) is important for improving the quality of such services. In this study, we prioritize and select performance indicators (PIs) for MSW service evaluation and organize them in a Balanced Scorecard (BSC) tool. The tool is applied for the period 2008–2011 to the public administration organization responsible for waste management in Loulé Municipality, Portugal, a region characterized by strong tourist seasonality. MSW management priorities are well established through EU directives and the application of PIs should allow service objectives to be quantified, including reducing the production of waste, increasing the quantity of recyclables, improving clients’ satisfaction with the service, improving workers’ motivation, decreasing the quantities of waste in landfills, and reducing service costs. The results indicate that the use of indicators and BSC tool can assess the strategic objectives of the organization and monitor its performance over time. The overall BSC assessment ratings were 51.7%, 66.1%, and 70.1% for 2009, 2010, and 2011, respectively, indicating an improvement in overall service performance over time. The results demonstrate that monitoring seasonal variations of PIs in tourist regions is important since these variations can help to explain annual changes in the factors affecting waste services management, their impacts on overall service quality, and the best time for measures to be applied. Based on this case study, the BSC can effectively contribute to improvements in the quality and cost of MSW services in areas characterized by strong seasonal variations in population and waste.