In this study, the effects of machining parameters on the material removal rate (MRR) and surface roughness (Ra) were investigated during the cutting of Al/B4C/Gr hybrid composites by wire electrical discharge machining (WEDM). Wire speed (W-S), pulse-on time (T-on) and pulse-off time (T-off) were chosen as the control factors. The L-27 (3(3)) orthogonal array in the Taguchi method was used in the experimental design and for the determination of optimum control factors. Response surface methodology was also used to determine interactions among the control factors. Variance analysis (ANOVA) was applied in the determination of the effects of control factors on the MRR and Ra. According to the ANOVA results, the most effective parameters on MRR and Ra were wire speed with a 85.94% contribution ratio, and pulse-on-time with a 47.7% contribution ratio. The optimum levels of the control factors for MRR and Ra were determined as A(3)B(3)C(3) and A(1)B(1)C(2). In addition, second-order predictive models were developed for MRR and Ra; correlation coefficients (R-2) were calculated as 0.992 and 0.63.