Sri Lanka has one of the highest incidences of human leptospirosis worldwide. Outbreaks of this zoonotic infection are related to the monsoons and flooding. The present study investigates risks associated with environmental, animal and occupational exposure. Data was obtained from structured interviews with 483 patients (276 cases and 207 controls). Risk exposures were studied for the entire population and for two stratified occupational groups, the non-paddy workers and the paddy workers. A higher odds ratio (OR) of leptospirosis transmission for paddy workers was observed compared to non-paddy workers (OR=1.907,95% CI 1.274-2.856). Rat exposure was not associated with a significant higher risk for any of the groups. Instead cattle and household animals seemed to be important for transmission of leptospirosis to humans, especially among non-paddy workers (OR=10.655, 95% CI 1.213-93.582). Leptospirosis in paddy workers was associated with environmental factors linked to contamination and wetness in paddy fields. Interestingly abandoned paddy fields were found to have a protective effect against transmission to paddy workers (OR=0.421, 95% CI 0.237-0.748). Keeping animals on these dryer fields may act as a boundary for contamination of paddy fields with infectious animal urine. This finding could be considered in public health interventions targeting leptospirosis among paddy workers.