Analyzing wireless communication performances by using information-theoretic results is of practical importance. In this paper, first, an achievable secrecy rate region and an outer bound on the secrecy capacity region for the discrete alphabet and memoryless wiretap channel with side information non-causally known at the transmitter are obtained. Then, by extending the results to the continuous alphabet wireless wiretap channel and by deriving a closed-form expression on the secrecy coverage region (SCR), as a remarkable wireless performance factor, impact of side information on the SCR is analyzed and it is shown that side information increases the SCR as expected intuitively. Numerical evaluation of theoretical results is done finally.