A radiotracer investigation was carried out in a wastewater stabilization pond using radiotracer technique. Residence time distribution (RTD) of wastewater was measured using Iodine-131 as a radiotracer. The measured RTD was treated and mean residence time (MRT) was determined. The measured MRT was compared with the theoretical MRT and dead volume was estimated. It was found that about 93% of the geometric volume within the anaerobic pond was dead. The measured RTD was modeled using various RTD models and eventually a suitable model was identified to describe and visualize the flow pattern of wastewater within the pond. Based on the measured MRT, estimated dead volume and identified flow patterns, it was concluded that the hydraulic performance of the anaerobic pond was very poor and not suitable for its intended purpose.