Applying the real options approach, this paper uses a jump-diffusion model with constant elasticity of variance (CEV) components by choosing a compound Poisson process to examine the investment opportunity. Through incorporation of unpredictable but sizeable changes in a firm's projected earnings, the jump-diffusion CEV model can depict the jump effect on earnings under investment uncertainty by modeling the constant volatility change over time, enabling evaluation of the probability that an investment will take place. Using the jump-diffusion CEV model, this study demonstrates that the critical investment value is an increasing function of jump size and a decreasing function of the CEV elasticity parameter. Furthermore, this paper shows that both the direction of the jump and jump frequency may influence the investment opportunity. Numerical results show that the probability of investment may increase when jumps are expected to be positive and more frequent in the earnings stream. Conversely, investment opportunity is likely to decrease with more frequent but negative jumps in expected cash flows.