A number of organic reactions using natural catalysts such as clay [50] -[53] , natural phosphate [54] [56] , animal bone [57] , and also various fruit juice’s are reported in literature. Due to acidic nature, aqueous fruit juice like lemon [58] -[64] , pineapple [65] [66] , coconut [67] , Acacia concinna [68] , Sapindus trifolistus [69] and Tamarindus indica [70] [71] fruit has been found to be a suitable replacement for various homogeneous acid catalysis. In accordance with this, we report the Knoevenagel condensation of aromatic aldehydes with malononitrile in presence of aqueous starfruit juice, a natural, green and biocatalyst system stimulated by visible light.