This paper reports the observation of steady-state, sub-Doppler light amplification by coherence in Doppler-broadened Λ-type Rb atomic systems formed by the Rb D2 transitions 5S 1/2 (F = 2) ↔ 5P3/2 ↔ 5S 1/2 (F = 3). The experiment was carried out in a 75-mm Rb vapor cell heated to about 60°C.