Abstract
This study aimed to describe the ability of students in making graphs of a rational function. The type of this research was qualitative research with a descriptive approach. The research subjects were undergraduate students in Mathematics Education department. Data were collected by giving rational function test to 34 students. The results of students' work were analyzed by identifying the tendency of error patterns and examining the causes of errors. The results showed that only 6% of 34 students were able to draw graphs of rational functions given precisely. Students tended to make mistakes when determining the vertical asymptote, the intersection of the Y-axis, also when determining the 'hole' location of a given rational function. Causes of errors could generally be categorized as procedural errors and errors due to lack of understanding of concepts, both concepts in the form of prerequisite material or subject matter.