Primary amoebic meningoencephalitis was first recognised by a South Australian pathologist. The histopathological appearances indicated that the organism, Naegleria fowleri, entered the central nervous system from the nasal cavity via the cribriform plate. But the mode of transmission remained unknown.To describe how the pathogenesis of this condition was discovered, and correct misinformation about the events and persons involved in this process.We hypothesised that pipeline water supplying northern centres in South Australia was responsible for transmitting thermophilic amoebae during the summer months.The evidence supporting our hypothesis was: domestic water pipelines were exposed to sunlight and became heated to 35-45 degrees C in summer which promoted the formation of vegetative forms of the amoebae; some patients described using tap water to flush their nasal cavities; and Naegleri fowleri were eventually recovered from domestic tap water supplies.A successful collaboration between general practitioners and laboratory scientists elucidated the pathogenesis of primary amoebic encephalomyelitis, a serious public health hazard in South Australia from 1947 until the early 1970s.