The giant magnetocaloric (MC) effect measured in Mn_0.5Fe_0.5NiSi_1-xAl_x alloys ( 0.05 £ x £ 0.07) for a low magnetic field change (|ΔS_M|^max ~16-24 Jkg^-1K^-1 at 2 T) 1, and the fact that they are based on cheap and abundant elements motivated the interest on their study. The effect is linked to their first-order martensitic-like magnetostructural transformation (MST) from a high-temperature hexagonal Ni₂In-type paramagnetic (PM) phase to a low-temperature orthorhombic TiNiSi-type ferromagnetic (FM) phase which is tunable over wide temperature range by changing the Al content 1,2. As melt spinning is a rapid solidification technique able to produce alloy ribbon samples with a high chemical homogeneity and may result very appropriate to fabricate these five-elements alloys, we produced Mn_0.5Fe_0.5NiSi_1-xAl_x melt-spun ribbons with x=0.055 and 0.060 that were thermally annealed at 1123 K for 4 h; their MST and MC characteristics were studied. RT XRD pattens show that samples are nearly single phase with a major Ni₂In-type phase coexisting with a minor amount of the TiNiSi-type one. DSC, M(T)^5mT and M(T)^2T curves, shown in Fig. 1, denote the occurrence of the MST with a large thermal hysteresis (~ 32 K), the substantial effect of Al-content on the tuning of the MST temperature without a significant change in the magnetization change across the MST which led to similar ½DS_M(T)½^max values (as Fig. 2 shows). The results are discussed and compared with previous data reported in literature for bulk alloys.