Determination of the flow characteristics is very important for the design of sanitary sewers in any area. In the present study these are determined in the running sewers for the two parameters; per capita flow contribution and the peak flow factor. ISCO area - velocity flow meter model 4250 is used for this purpose. The flow meter, before being used in the running sewers, is calibrated first in the Hydraulics and Hydrology Laboratory of the UTM (Universiti Teknologi Malaysia). During the study the flow meter is installed inside the manhole in 10 different phases in the months of June, August, September, and October 2005 to monitor the sewage flow running in it. Continuous data is recorded in the flow meter during the process and the recorded time varies between 47 hours 25 minutes and 128 hours 35 minutes. The rainfall data is also collected during the same time using an automatic rain gauge which recorded rainfall at every five minutes of interval. Both the parameters thus calculated are then compared with the Malaysian Standard for sewer design i.e. MS 1228:1991. The results show that higher values of these parameters are being used in the design of sanitary sewers and extensive study needs to be carried out to review these values for future use