This paper examines the relation between business strategy and labor investment efficiency. Since business strategy affects both the agency problem and firm-level uncertainty, as well as the overall shape of corporate behavior, we would expect the efficiency of labor investment to vary with the particular business strategy a firm pursues. Using a large sample of US data, we find that firms having a prospector-type business strategy are associated with inefficient labor investment, while those having a defender-type business strategy are associated with efficient labor investment. We provide evidence that uncertainty, rather than the agency problem, causes prospector-type firms to exhibit inefficient labor investment. Finally, we document that inefficient labor investment by prospectors leads to relatively low profitability in subsequent periods. These findings are robust when subjected to a series of sensitivity tests.