Genetic screening can identify individuals with increased susceptibility to certain workplace toxicants. One conceivable benefit is a reduction in occupational disease costs. We examine this rationale by considering the associations among genetic traits, exposure, disease risk, and disease incidence. Given appropriate information, we describe methods for computing the expectation and variance of the future number of disease cases and of the differential screening cost per worker hired (a cost-benefit measure). We present two hypothetical scenarios: (1) benzene-induced cancer with few expected cases, and (2) chronic beryllium disease with many expected cases. We show that variability in disease incidence and cost outcomes must be considered because in specific instances, screening can be cost-beneficial on average but yield an unfavorable outcome with high probability. This circumstance pertains to scenarios involving small differences between the expected number of cases in screened versus unscreened cohorts.