Ammoniated natural rubber latices were found to be destabilised under high pressure at 1 GPa and -20 o C. However, the latices remained stable when the high-pressure treatment was carried out at room temperature or 50 o C. No significant changes were observed in the particle size distribution of the latices after the treatment. The rubbers coagulated from high-pressure treated latices generally showed a small increase in the gel content and narrower molecular weight distribution when compared to the control samples. High-pressure treatment led to a significant increase in the extractable protein content of the rubber films, indicating the occurrence of protein degradation during the treatment. However, the corresponding allergen content of the film was found to decrease drastically after the treatment, showing that the active site of the allergen could be destroyed by high-pressure treatment without sacrificing the properties of the rubber.