Al-rich portion of the Ir–Al phase diagram has been investigated with 10 alloys by means of differential thermal analysis, X-ray diffraction, scanning electron microscopy, inductivity coupled plasma spectrometry and electron probe microanalysis. Invariant reactions are observed: L↔AlIr+Al 2.7 Ir, L+Al 2.7 Ir↔Al 3 Ir, L+Al 3 Ir↔Al 13 Ir 4 , L+Al 13 Ir 4 ↔Al 9 Ir 2 . Although the eutectic reaction, L↔AlIr+Al 2.7 Ir, cannot be regarded as definitely established by previous research, it is confirmed in the present research. Liquidus curve has been determined for the first time for Al-rich alloy (Ir≤33.0at%). The Ir–Al binary phase diagram has been modified based on these experimental observations.