The study focused on usage and user satisfaction of undergraduates of the library facilities provided by the library of the Institute of Indigenous Medicine, University of Colombo. The objective of the study was to determine the users' satisfaction with information resources and services provided by the library. Also, it was aimed to investigate the purpose and frequency of library visits by undergraduates, to examine frequently used information resources and services, to find out undergraduates' perceptions regarding future developments of the library and to provide suitable recommendations to meet undergraduates' unmet needs. A structured questionnaire was used to collect data. Among the total students of Level 1 to Level 5, 20% of students from two Departments of Ayurveda and Unani were randomly selected as the sample. A number of 202 questionnaires were distributed and 154 students responded. The achieved response rate was 75.7%. Data were analyzed using SPSS and Wilcoxon signed-rank test was used to analyze the Likert scale responses. The study revealed that the majority of undergraduates, 77.3% of the Institute of the Indigenous Medicine were satisfied with the resources and services provided by the library and they had a positive perception of the library. The study especially revealed that existing electronic resources in the library were inadequate. Hence, steps should be taken to further the development of e-resources that effectively meet the needs of undergraduates. Improving the physical facilities and reading environment of the IIM library deserves high priority. Conducting more user awareness programs is a necessity. This should be apart from the orientation programs. Implementing marketing strategies on library resources and services needs to be raised.