Agro-industrial wastes possess highly-valuable bioactive compounds. Recently, they have been taken into account as an alternative source that can be used as raw material for various industries. Such an approach can help to reduce both production cost and pollution load. In this study, the usability of pomegranate peels and olive leaves, defined to be agricultural and industrial residues, as a combined tanning agent in leather industry was investigated. For this purpose, first of all pomegranate peels and olive leaves were extracted for determining their tannin contents and then they were used in tanning process for evaluation their combined tanning ability. Shrinkage temperature (76.5 °C) resulted from this combination tanning and the mechanical properties of the tanned leather revealed that pomegranate peels and olive leaves can be evaluated as an alternative, satisfying combination of tanning material for leather industry.