Oleg Safronov The amount of discrete spectrum of a perturbed periodic Schr\"odinger operator inside a fixed interval $(\lambda_1,\lambda_2)$ (195K, Postscript) ABSTRACT. In this paper we extend the results of \cite{Sa} for a more general class of perturbations. Let $A$ be a periodic Schr\"odinger operator and let $V\geq0$ be a decaying potential. We study the number $ \tilde{N}(\alpha)$ of the eigenvalues of the operator $A(\alpha)=A-\alpha V$ inside a fixed interval $(\lambda_1,\lambda_2)$. We obtain an asymptotic formula for $\tilde{N}(\alpha)$ as $\alpha\to\infty$.