Key advantages of a Ventilated Improved Pit (VIP) toilet over alternative low-cost sanitation facilities are its ability to dispel odours and to minimize fly populations. To assess these purported benefits in a field setting, thirty toilets in six Upper West Region communities were monitored from September through November of 2007, modeled, and then compared to the World Bank/UNDP Technical Advisory Group specifications. The evidence suggests that the requirements for achieving beneficial performance are often ignored; hence VIP toilets are not the best sanitation facility for this region. This article details VIP ventilation and fly control mechanisms identified in the 2007 study and assesses their effectiveness; in practice, both fail to meet design specifications.