Hospitals as health service providers, when patients feel satisfaction with the health services provided, this has a positive impact on the patient's recovery process. In serving patients, the concept of Response Time refers to the length of time staff are able to treat patients upon arrival at the health service unit, with a time of ≤ 5 minutes. Efficient service provision, namely characterized by fast response times, can contribute to overall patient satisfaction in the emergency department. The aim of this research is to determine the relationship between Response Time of services in the ER and the level of patient satisfaction at the Muhammadiyah Gresik Hospital. This research uses an analytical survey design with a cross-sectional approach. Researchers used an accidental sampling strategy, a population of 317 respondents. The research sample consisted of 176 individuals who sought treatment at the Muhammadiyah Gresik Hospital Emergency Room. The tools used in this research consisted of a Response Time observation sheet and a patient satisfaction level questionnaire sheet. Almost all service response times in the emergency room at Muhammadiyah Gresik Hospital are in the fast category, as much as 80%. Half the level of patient satisfaction in the satisfied category is 41%. From the chi-square statistical test carried out to analyze the relationship between response time and the level of patient satisfaction in the Muhammadiyah Gresik emergency room, it produces a P-value of 0.000 with α = 0.05. There is a relationship between response time and patient satisfaction level in the emergency room at Muhammadiyah Gresik Hospital. Patient satisfaction shows the nurse's ability to meet patient expectations for high quality services