Nowadays, customer is believed to be the most precious asset for any organization and building a long term relationship between firms and customers plays essential role for the success of organizations. This paper presents an empirical investigation to study the relationship between after-sales service quality and customer satisfaction in a firm named Setareh Nik Aria Yadak whose primary responsibility is to provide after-sales services for public transportation. The study selects a sample of 252 out of 730 customers in 2015 who received their services from this firm. The survey designs a questionnaire in Likert scale, which consists of four items of quality, responsiveness, speed and cost of services. Cronbach alpha is calculated as 0.79, which validates the quality of the survey. Using Spearman correlation test, the study has detected a positive and meaningful relationships between four components of after-sales services and customer satisfaction.