A study examined factors influencing imposition and collection of probation fees in a sample of more than 2,400 Illinois adult probationers. The study grouped probationer variables into two major categories (probationer and sentence characteristics), and studied four different measures related to probation fees: (1) whether probation fees were imposed; (2) when imposed, the total amount of probation fees ordered; (3) the monthly rate of probation fees; and (4) the percentage of fees paid/collected. Multivariate analyses revealed that some factors were consistent predictors of all measures of probation fees (imposition, amount, and collection rates), while other factors were predictive of only some measures. Probationer characteristics, including race, income, and prior convictions, were predictive of whether fees were imposed and the collection rate, while environmental conditions, such as whether the probationer was sentenced in a rural jurisdiction or whether other financial conditions of probation were imposed, such as criminal fines, were predictive of all three measures of probation fees. Tables, references