This paper reports the data obtained on an attempt at the utilisation of the sludge which is a dumped waste of petroleum refineries. This sludge after purification was used as a processing aid in the sulphur vulcanization of natural rubber where carbon black is used as filler Different mixes, containing varying concentrations of aromatic oil/refinery sludge were prepared. These mixes were evaluated for their cure characteristics and the vulcanizates were tested for various physical properties and crosslink density including ageing. Purified refinery sludge can substitute for the conventional process oil without much affecting the cure properties of the mixes.