The Moderate Resolution Imaging Spectroradiometer, MODIS, is designed to be able to measure concentrations of the photosynthetic pigment chlorophyll-a in oceanic surface waters to give an indication of phytoplankton abundance. However, accuracy of satellite-derived chlorophyll-a estimations is known to be limited in coastal waters where water constituents other than phytoplankton affect the optical properties of the water. Thus it is necessary to determine the accuracy of satellite-estimated chlorophyll-a imagery in a region such as the coastal waters of South Australia before applying such products with confidence. MODIS-derived chlorophyll-a estimations were compared to field-based measurements of chlorophyll-a concentration in a number of locations within the coastal waters of South Australia. Results have shown that shallow water depths of 20 m or less bring about MODIS-derived chlorophyll-a concentrations that are elevated above in situ measurements, most likely as a result of bottom reflectance. Otherwise MODIS chlorophyll-a concentrations have performed within reasonable accuracy with R² values between MODIS estimations and field-based chlorophyll-a measurements in the order of 0.80 and rms errors of less than 30%. The study has shown that care needs to be taken when interpreting outputs of MODIS-derived chlorophyll-a imagery in shallow coastal regions, but otherwise MODIS chlorophyll-a imagery is able to measure the surface chlorophyll-a concentration in South Australian coastal waters within modest accuracy and can be applied to investigate phytoplankton dynamics of the region.