Medan Zoo is located in Simalingkar Village B, Medan Tuntungan, about ten kilometres from the city centre towards Berastagi. Based on data obtained Medan Zoo has not been able to realize the amount of revenue that has been targeted. The present study aims to analyze the effect of service quality consisting of tangible, reliability, competence, courtesy, credibility, security, responsiveness, accessibility, communication, and understanding the customer to Medan Zoo visitors partially and simultaneously. The type of research is quantitative descriptive research. The questionnaires were distributed to a hundred visitors to Medan Zoo. Simultaneously, it has been found that there is a significant influence of service quality consisting of tangible, reliability, competence, courtesy, credibility, security, responsiveness, accessibility, communication, the customer's understanding on visitors’ satisfaction at Medan Zoo