The main objective of this research was to study the occurrence of Giardia in selected water supplies and watershed animals in Connecticut. Water samples were collected monthly using the E.P.A. approved Giardia sampling method at selected water utilities and analyzed for Giardia cysts. With every Giardia sample collected, samples were tested for: total coliform, fecal coliform, standard plate count, yeast, turbidity, and pH. Fecal specimens were collected then analyzed from beaver, deer, squirrel, muskrat and raccoon if these animals were found on the watershed. Attempts to correlate the presence of Giardia cysts with the collected water quality data were not successful. Six out of 413 animal fecal samples were found to be positive for Giardia from samples collected on the reservoir watershed. Collection of fecal samples from trapped animals yielded a slightly higher percent positivity than fecal samples collected from live animal droppings.