The high population in the city of Yogyakarta has the potential to cause traffic jams. One of the alternative modes of transportation to overcome these transportation needs is the Electric Rail Train. KRL has advantages over other universal transportation, including speed of travel time, connectivity, seat compliance, and ease of buying tickets. This study aims to analyze how much influence the quality of service performance has on the level of customer satisfaction of users of Yogyakarta-Solo Electric Rail transportation services. This research was conducted using a questionnaire method which was distributed to KRL users as many as 100 respondents using a method non-probability sampling with a convenience sampling technique and quantitative analysis was carried out in the form of validity and reliability tests, Importance Performance Analysis (IPA), Customer Satisfaction Index (CSI). The results of the study from Importance Performance Analysis obtained a 92% level of conformity, it can be said that the level of conformity of consumer expectations, in this case, is still below consumer expectations, and overall service still needs to be improved. 5 attributes have a high level of importance but the level of performance is still lacking, including special facilities for people with disabilities, health protocol supporting facilities: hand sanitizer, masks, etc., availability of evacuation equipment during an emergency, Ease of obtaining information on KRL services (schedule and ticket prices), KRL trip disruption information. Research results from the Customer Satisfaction Index 82.77%. This value shows the satisfaction of users of the Yogyakarta-Solo Electric Rail Train "Very Satisfied" with the service performance in the Yogyakarta-Solo Electric Railroad series.