Toroidal drift mode features and stability are studied, using a fluid description, for a plasma with two ion species: impurity and main ions. Impurity and main ion temperature gradient (ITG) modes dominate for larger temperature gradients, &eegr;i≳1, while dissipative trapped electron (DTE) and impurity‐induced modes are present also for &eegr;i<1. Simple analytical expressions for the stability thresholds are derived from conditions given by the impurity and main ion fluids.