Abstract: Premised on the lack of development studies on lakes (as the field is dominated by limnology and aquaculture studies), the scarcity of small-lake studies (as the field is heavily concentrated on big-lake studies) and the absence of operationalized description of small lakes (as there is no existing definition of small lakes in the country), this study assesses the intricacies of the administration and development of Yambo Lake, a small transboundary lake. The study shows that despite existing favorable conditions, development is progressing slowly in Yambo Lake aquaculture has significantly declined and organized tourism is only just evolving. It contends that the administrative agencies (i.e., the Laguna Lake Development Authority, the City Government of San Pablo, the Local Governments of Nagcarlan and Rizal, Laguna) must now accelerate their collaboration to have a zoning-development plan (as it is crucial for the proper and efficient management of the lake) and institutionalized ecotourism (as it is critical to expand livelihood opportunities of the locals and enhance their community).