This research aimed at analyzing the effect of retail mix towards purchase decision of customers at Naraya Supermarket of Kasihan District simultaneously and partially. The subjects of this research were consumers who have ever shopped at Naraya Supermarket of Kasihan District. In this research, there were 100 respondents who were selected using convenience sampling method. Meanwhile, the data were analyzed using SPSS 22 with double linear regression to find the forms of simultaneous effect and partial effect of independent variable (X) and dependent variable (Y). Simultaneous test was conducted using F test, while partial test was done using t test. Based on the analysis, the research result shows that product, price and the atmosphere of shop has significant effect towards purchase decision. Meanwhile, other retail mix variables which are promotion, service, shop design, and shop location do not affect purchase decision at Naraya Supermarket of Kasihan District. This research also proves that simultaneously, retail mix variable has significant effect towards purchase decision.