Abstract: The present study, was carried out during June 2009 till March of 2010, involved the monitoring of some surface water quality indices related of water stream running through Riyadh, Saudi Arabia. Water samples were collected from 10 different locations along the course of the stream. The samples were analyzed for dissolved oxygen, Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Oxygen Content (TOC), total petroleum hydrocarbon, oil and grease, total viable counts measured at 22°C, 72 h and 37°C, 24 h, total coliforms and feacal coliforms. The results indicated that the water quality varied depending on the time of sampling (month) and the specific location. Poor quality was also recorded at some of the locations owing to the contamination by mixing of industrial effluents. The present study emphasizes on the need for continuous monitoring of the water quality to control the water pollution level of the main stream. The results reported in this study are also deemed to serve as baseline studies on the surface water pollution status of the main stream in Saudi Arabia.