Description: This article pertains to the optimal asset allocation of surplus from an insurance company model. The insurance company is represented by a compound Poisson risk process which is perturbed by diffusion and has investments. The investments are in both risky and risk-free types of assets similar to stocks/real estate and bonds. The insurance company can borrow at a constant interest rate in the event of a negative surplus. Numerical analysis appears to show that an optimal asset allocation range can be estimated for certain parameters and compared with insurance data. Using a conservative method to minimize the probability of ruin, a reasonable optimal asset allocation range for a typical insurance company is about 4.5 to 8.2 percent invested in risky stock/real estate assets. An inequality and the exact solution are obtained for the pure diffusion equation. In addition, the asymptotic form of the ruin probability is shown to be a power function.