The objective of this study is to find appropriate finance wastewater treatment systems of Bangkok Metropolitan, using qualitative analysis, and exploring the experience of Pattaya, Pathong and Bangkok garbage fee collection. The results of this study suggest that Bangkok Metropolitan Administration (BMA) has insufficient capability to collect fees for wastewater treatment. BMA is still unable to launch wastewater treatment fee municipal law because of the needs to deliberate numerous laws which do not allow BMA to charge such fees without reservation. From experience of Pattaya, Pathong and Bangkok garbage fee collection, reasonable fees and efficient collection systems seem to be key factors that determine a "successful" system. Reasonable fees which recover only operating and maintenance cost (O&M cost) will not put too much burden on payers, thus assuring cooperation in compliance. Efficient collection leads to the capability to collect fees that cover a large number of households, having low overhead costs and generating sufficient income to cover O&M costs. Most likely, BMA policy is to apply fee of 2 baht per cubic meter for any inhabitants settling in boundary of services from Sri Phya, Ratanakosin and Chongnonsri operating wastewater treatment plants. This charge rate is sufficient to cover the average O&M costs of all three systems that are about 1.97 baht per cubic meter. There are ways to collect these fees either by BMA itself or by the Metropolitan Waterworks Anthority (MWA). BMA can either collect fees from household directly or let households pay at district offices. The analysis in this study shows that MWA should collect the fees because of the good coverage of 98.46% of water users. This will generate monthly net income of about 347,876 baht per month after deducting O&M and administrative costs. Moreover, comparing to BMA, MWA has lower administrative costs. Thus, BMA should seek cooperation from MWA to collect wastewater treatment fees. However, there is a limitation. Households, which settle in wastewater treatment area, but not in MWA accounts would be free riders. The solution is, therefore, to have BMA dealing directly with these users.