Worldwide, diarrhea disease, which causes about 2.6 million deaths annually, mostly among children less than 5 years, is primarily spread through food and water contamination. This is often the result of poor sanitation and hygiene associated mostly with crowded urban and peri-urban settlements. One major area of concern is the disposal of greywater from the unsewered low income, high density population areas of the municipality. Integration of conventional sanitation systems in these areas has been a major challenge due to unplanned settlement structures and the limited available space. The aim of this study was to design and evaluate the treatment performance of horizontal subsurface flow constructed wetland systems (HSF CWs) for treatment of greywater to meet the water quality control standards for safe disposal under the principles of sustainable sanitation. HSFCW system experimental plots treating greywater from domestic households were established. The performance results indicate that this wetland system has excellent removal capability for biochemical oxygen demand ranging from 97.3-99%. Consequently, oxygen demand exerted by micro-organisms to oxidize organics present in greywater during the 48 hours HRT dropped by an average of 97.3%. This study has the aim of informing greywater management decisions for urban and peri-urban areas. This knowledge supports formulation of control measures at the source and designing of an appropriate treatment system for safe reuse or disposal.