In the framework of the effective-mass approximation and using a variational approach, we present a systematic study of the excitonic states in CdTe/Cd_1−xZn_xTe cylindrical quantum dot as a function of the dot size, temperature and composition. The photoluminescence line intensity temperature dependence is also investigated. Our results show that the stability of the exciton is more influenced by the dot size and temperature factors. Furthermore, the photoluminescence intensity depends strongly on the temperature, dot size and composition.