In vitro effects of triacontanol (TRIA) on antioxidant enzymes and photosynthetic characteristics were studied in Arachis hypogaea L. cultivars (M-13 and PBS24030). The in vitro impact of TRIA on multiplication potential was also evaluated, which was found to be best at 2.0 ml L-1 TRIA in combination with 6- Benzyl adenine (BA, 3 mg L-1) in both the groundnut cultivars. Rhizogenesis was observed in almost all the TRIA treated cultures in both the cultivars. Moreover, shoots failed to set roots, in the presence of BA. Total chlorophyll content, total soluble sugars, total soluble proteins and ascorbate peroxidase (APX; EC 1.11.1.11) activity were found to be increasing with increasing concentrations of TRIA, whether alone or in combination with BA, however, genotypic differences were observed in case of Hill reaction activity (HRA) in between the cultivars. Best catalase (CAT; EC 1.11.1.6) activity was reported at 1.0 ml L-1 TRIA with BA (3 mg L-1) in both the cultivars. Peroxidase (POX; EC 1.11.1.7) and polyphenol oxidase (PPX; 1.14.18.1) activity was maximum at 1.0 ml L-1 TRIA with BA (3 mg L-1) in M-13, whereas at 2.0 ml L-1 TRIA with BA (3 mg L-1) in PBS24030. Lipid peroxidation was found to be reduced with the supplementation of TRIA. The results obtained in the study clearly indicated not only the in vitro establishment of groundnut cultivars in the presence of TRIA but also its effect on various growth promontory physiological parameters.