This paper presents a detailed experimental investigation on single point incremental forming (SPIF) of AA5052 sheet. In order to investigate the effects of incremental forming parameters, a straight-groove test was designed using L18 orthogonal array (OA) and groves were performed along the rolling, transverse and 45° (diagonal) directions on the cold-rolled sheets. The sum of major strain and minor strain as a measure of formability and the surface roughness were measured. These multi-objective responses were normalized using grey relational analysis (GRA). Moreover, the principal component analysis (PCA) was applied to evaluate the weighting values corresponding to each performance characteristics. The variability caused by the input parameters was apportioned using analysis of variance (ANOVA). Thus, the Taguchi method (TM) based GRA coupled with PCA was specifically adopted to determine the optimal combination of forming parameters. The confirmation experiment shows an average improved formability of 56.37% and surface roughness of 93.68%.