We investigated the treatment of malachite green (MG) dye using sonocatalytic, photocatalytic and sonophotocatalytic techniques. The percentage of decolorization for sonophotolysis (65.5±3.3%) was much higher than the individual effects of sonolysis (55.2±2.4%) and photolysis (52.1±2.6%). The efficiency of the sonophotocatalytic process increased in the presence of photocatalysts such as anatase TiO2 (82.2±4.1%) and ZnO (75.7±3.8%). The decolorization rate further enhanced in the presence of nano-TiO2 (anatase, rutile ratio 75 : 25 and particle size ≤100 nm). The enhancement in decolorization was marginal for sonophotocatalysis (95.9±4.8%) as compared to sonocatalysis (93.0±4.3%) and photocatalysis (93.2±4.6%). The intensification of decolorization in the presence of nano-TiO2, due to lower recombination of hydroxyl ions on the photocatalytic surface and nano-particle size of a catalyst, increased cavitational activity. The total organic carbon was found to be maximum for sonophotocatalytic in the presence of nano-TiO2 (67.1±3.3%).