A necessary and sufficient condition is obtained for oscillation of bounded solutions of second order impulsive delay differential equations of the form(r(t)x′(t))′ + p(t)f(x(&tgr;(t))) = 0, t ≠ &thgr;i, &Dgr;(r(&thgr;i)x′(&thgr;i)) + big(x(&sgr;(&thgr;i))) = 0, i ∈ Z, &Dgr;x(&thgr;i) = 0. An example is also inserted to illustrate the effect of impulses on the oscillatory behavior of the solutions. © 2004 American Institute of Physics