Cameron Highlands is experiencing rapid development as a popular tourist destination in Malaysia. This causes a rapid boost in construction and other tourism-related activities, such as the growth of vegetables, fruits and flowers. Due to that, the water quality of rivers in the highlands has been adversely affected. In this study, Bertam River, as one of the main streams in Cameron Highlands, was monitored to assess its suitability for recreational activities and conservation. Seven sampling points were selected in the river and tributaries: dissolved oxygen, biochemical and chemical oxygen demands (BOD and COD), total suspended solids (TSS), ammonia nitrate (NH3�N) and pH were measured and the water quality index (WQI) was computed during high and average water flow. In addition, water quality surface data were generated from the sampling points using the interpolation technique of geographic information system to predict values of unknown locations. Results show that TSS, BOD and NH3�N contribute most to the pollution of the waters. This is due to earthworks in the highlands as well as poorly treated sewage discharges from hotels, rest houses and apartments. WQI results indicate that Bertam River and its tributaries are classified as class II, III and IV, which require extensive treatment before utilization in most of the locations. Consequently, to improve the water quality of the rivers, recommendations have been made to ensure that some sampling points with potentials for recreational activities attain class II and subsequently class I in the near future. © 2014, Springer-Verlag Berlin Heidelberg.