Abstract: Introduction: The evaluation of training services quality in training centers is one of the major steps in improving quality. Deciding the amount of difference between the present condition and expected condition can facilitate the promotion of training services quality. Methods: This study was a descriptive–survey. The population size was the 1217 learners attending the on-the-job training courses in training centers (computer, Technical-specific and management) in the Training and Development Department of National Iranian South Oil Company (NISOC) in the second half of 2014. The sample volume was decided 292 people using the Cochran Formula (1977).The sample size of each training center was chosen based on the percentage of the learners in the population size using the random-stratified method. The data collection was done via SERVQUAL standard questionnaire. The questionnaire measured the gap in the five dimensions of service quality. The data were analyzed using SPSS software as well as conducting descriptive statistics, Wilcoxon and Kruskal-Wallis Test. Results and Analysis: The findings showed no gaps for the two dimensions of empathy and reliability and a negative one for the tangible (-0.66), responsiveness (-0.41) and assurance (-1.44). No difference was found between the quality of training services in training centers. Conclusion: Although the mean of percent condition is higher than the average(4.01) but the observed gap between the expectations and perceptions proves that the learners expectation for the provided services were not fulfilled. As a result it is suggested that for establishing the customer-care culture, the dimensions which had the biggest gap be prioritized when allocating the budget.