The number of population in this study was 118 respondents with a sample size of 35 respondents because of the sampling method using purposive sampling method. The method of analysis used in this research is the validity and reliability test where the result of each variable is valid, from the analysis of regression equation: Y = 6,716 + 0,224X where X is management information system variable, and Y is decision making variable. From t-test obtained t count (2,860) Ëƒ table (1,692) that management information system has a positive and significant effect on decision making. From the result of determination coefficient determination (R2), decision making can be explained by variability of management information system variable equal to 0,199 or 19,9%, while the rest 80,1% is explained by another variable not included in the regression model of this research. We recommend that the Badan Pertanahan Nasional (BPN) Medan maintain and develop existing management information systems in accordance with the development of information technology, such as documenting every incoming and outgoing data so that every staff ranks easier to search, process information, so that facilitate decision-making activities.