This paper presents the stability data of partially premixed LPG-air flames issuing from a central pipe of 9.5 mm diameter in a co-axial burner. The burner is operated in co-flow or swirl mode of secondary air surrounding the flame base. For the range of fuel flow rates studied, the results show that lift, drop-back and blow-out velocities are higher for the flames operating with external swirl-air. Flame stability is seen to deteriorate in co-flow mode and flame drop-back is also not exhibited. The higher blow-off velocities observed in swirl mode are attributed to higher residence time for the reacting mixture around the flame base. The stability data obtained are found to be consistent with the flame stability models in the literature.