Metallurgical slags are produced in a very large amount in pyrometallurgical processes and are huge sources of waste if not properly recycled and utilized.This study reports the effect of fine ground copper slag & lead zinc slag on hydration kinetics and mechanical properties of Portland Pozzolana cement (PPC).PPC replacement level 0, 5 & 10% by mass of both the slags of particle size 4.6 μm & 8.8 μm (d50) were tested and evaluated for mechanical properties such as compressive strength, hydration kinetics and leachability of heavy metals.Mortar compressive strength worked out in compliance with IS-4031.The hydration kinetics was studied using powder XRD and Isothermal conduction calorimeter.Leachability of each specimen was evaluated following USEPA guidelines.The presence of ground non-ferrous slag in cementitious system manipulates its setting behavior.Increased PPC replacement levels by 10% increases strength by over 5% from 28 day onwards.The result of hydration study reveals participation of ground slag in hydration of PPC cement.Hydration kinetics of the PPC cement pastes studied with slag exhibits similar trend.However quantum of energy released differs with varying % of ground slag.The leaching results indicated that selected heavy metal ions from the cement matrix was low and did not exceed the US-EPA limits.The lime reactivity tests on both the slag indicate that the slag participates in the cement hydration reaction and corroborates the above observation.The study indicates potential beneficial aspects of both ground copper & lead zinc slag as a substitute material in PPC for conserving natural resources, energy and reduces pollution.