This study investigated the level of undergraduates' satisfaction and their perceptions towards library resources and services provided by the Science Library, University of Peradeniya. The survey research method was adopted to achieve the above objectives. A questionnaire was administered to 442 undergraduates of the Faculty of Science. 371 duly filled questionnaires were returned, were then analyzed. The findings revealed that more than 60% of the undergraduates visited the library daily and weekly, while more than 80% of them visited the library for multiple purposes. Regarding the available resources, the majority of the undergraduates were satisfied with the library book collection, periodicals and available magazines. Yet, only 39% and 32% of students reported that they were satisfied with e-resources and audiovisual materials available in the library respectively. Considering the library services, the majority of respondents were satisfied with lending, reference, referral and photocopying services. However, 11% of them were not satisfied, where as 13% of the students were not even aware of online services provided by the library. Further, the findings demonstrated that limited number of