Abstract Objective: To investigate the relationship between risk of Ross River virus (RRV) infection and proximity to mosquito‐breeding habitat surrounding a tidal wetland ecosystem in south‐west Australia. Methods: Geographic information systems (GIS) were used to spatially map cases of RRV disease in the Leschenault region between July 1995 and June 1996. Half kilometre buffer zones were constructed around the Leschenault Estuary and associated waterways; RRV disease case counts were calculated for each zone. Results: Different relationships between RRV disease incidence and proximity to saltmarsh mosquito habitat were observed east of the Leschenault Estuary compared with an urban region to the south. Disease incidence showed a decreasin...