We develop the stability and bifurcation analysis of controlled CSTR in the presence of a nuth order exothermal reaction. Theoretical bounds for the stability region are obtained in terms of the control parameters and bifurcation diagrams in the region of instability are discussed in order to illustrate the transition to chaotic behaviour. The analysis presented is based on the Pellegrini-Biardi model of control, but is equivalent to the more usual coolant flowrate control scheme in mixed reactors. In order to represent a more reliable physical situation, the influence of time delay on the control rule is discussed and a globally stable adaptive control proposed.