A novel mixed-ligand [Ru-III(amp)(pic)(H2O)] complex (1) (H(2)amp = N-(hydroxyphenyl)salicyldimine; pic = picolinate) has been synthesized and characterized by physico-chemical methods. Complex 1 has been found to be an effective catalyst in oxo-functionalization of C-H bond of organic substrates by using tert-butyl hydroperoxide (t-BuOOH) as a terminal oxidant. Formation of a high valent Ru(V)-oxo species as catalytic intermediate is proposed to be the source of oxygen atom in the oxidised product.