High entropy alloys (HEA) or Multi-principal elements alloys (MPEA), particularly precipitation-strengthened alloys, have great promise for structural applications. In this study, several alloys based on Al2 (Co, Crx, Fey, Ni)14, where 1≤x,y≤2 and x+y=3, are investigated to determine their mechanical properties, aging response, and precipitation behavior. Samples were initially homogenized, followed by water quenching, and then aged at 400 °C with periodic hardness measurements. The susceptibility of the alloys to hot rolling deformation and its effect on precipitation behavior was also investigated. Microstructural and phase characterization was carried out using x-ray diffraction, scanning electron microscopy, hardness testing, and transmission electron microscopy. Hardness measurements (or the aging curve) were directly related to microstructural evolution, for example, precipitate size, density, and its distribution. Precipitation behavior was modelled using ThermoCalc and subsequently validated through experimental work.