Thanks pal for the welcome and reply! I still don't know how to post pics here, but it's basically an inv voltage feedback amplifier with Rf=10k and Rin=1k. The output has 100ohms load, and doesn't drive a capacitor. I said both inputs are grounded because I am testing the circuit for the Vos and the supply current when input is zero. The circuit is on some kind of a test board. Supplies are properly bypassed by 0.1uF. I am thinking that stray capacitance at the output might be causing it to oscillate, because the part itself has been tested on the bench without oscillation, with the theory behind that the stray capacitance adds additional phase shift to the amplifier causing it to be unstable. Is it correct to say that some noise being picked up by the part on the ckt system triggeres the oscillation? Do you agree with my theory?