Malaria and other transient illnesses have been recognized as factors constraining economic development in tropical countries. The purpose of this paper is to determine the direct and the indirect impact of transient illness shocks, caused primarily by malaria but also including other tropical illness, on family labor use in irrigated rice production in Mali. Family labor is the most important factor of production used in rice production in Mali and transient illness shocks may negatively impact labor supply, production and hence household welfare derived from agricultural income and consumption. Two labor demand models are estimated to determine whether illness does indeed reduce labor supply: one where the dependent variable only includes family labor and a second that combines family and hired labor. These models can be used to test two sets of hypotheses on the relationship between illness and labor supply. First, we hypothesize that short-term transient illness shocks affect household labor supply implying that intrahousehold coping mechanisms are not wholly effective. Secondly, we hypothesize that hired labor markets are ineffective in mitigating illness shocks. We find that direct and indirect health shocks reduce the effective supply of labor and that neither household nor market supply of labor can mitigate these shocks.