The magnetic behavior of Ni 2+x Mn 1−x Al alloys around the stoichiometric 2:1:1 composition was investigated with several experimental techniques. The results of low-temperature magnetization measurements indicate that a competition mechanism between ferromagnetism and antiferromagnetism is expected in off-stoichiometric alloys. Although the Curie temperature is strongly dependent on the composition, the saturation magnetization has an unsystematic variation for deviations from the stoichiometric Ni 2 MnAl alloy. A reentrant-spin–glass behavior is observed below 50 K.