This paper specifies a flexible model of labour demand in Tunisian manufacturing industries. The model is further extended to incorporate a risk function part which allows identifying the determinants of both level and variations in employment. The risk function is important when designing public policies. It allows for the identification of industries suitable for targeting policies. The paper looks at the efficiency of the manufacturing industry in their choice of level of employment necessary to produce a given level of output. The results show that labour demand responds mostly to wages, followed by capital stock changes, and level of output.