Nationally, the number of operating farmers' markets has increased 111% from 1755 markets in 1994 to 3706 in 2004. Indiana's farmers' markets have increased at double the rate in the same timeframe. An Internet and mail census was sent to market managers to assess operational procedures and factors that influence customer and vendor participation in the market. A two-stage least squares model was estimated for the vendor and customer model. Paying fees and the number of customers present were the two variables that had a significant, positive influence on vendor participation. The presence of WIC, number of products available, the absence or presence of live music, absence or presence of cooking demonstrations, and number of vendors were significant for the customer model. The absence or presence of concession stands and picnic areas was significant at the 0.10 level in the customer model.