Microplastic is a term used to describe fragments of plastic 5 mm or smaller. Sources of aquatic microplastic pollution include microbeads used in personal care products such as facial scrubs and toothpastes, pellets used as precursors for industrial products, plastic fibers derived from washing clothes made with synthetic materials, and fragments of larger plastic items. Motivated by recent state and federal efforts to ban microbeads in personal care products, the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) characterized Bay surface waters and wastewater treatment plant (WWTP) effluents for microplastic contaminants. Nine Central and South Bay surface water samples were collected using a manta trawl. Two-hour sieved samples of effluent were collected from eight WWTPs discharging to the Bay. Microplastics in samples were characterized by size, type, and abundance. Preliminary results from this survey for plastic pollution in the San Francisco Bay are presented.