Foot position affects postural stability during upright standing; however, conflicting indications have been reported for the ideal foot placement during stabilometric exams. The aims of this study were to evaluate (1) the correlation between anthropometric measurements (AMs) and between-feet measurements (BFMs) in self-selected comfortable foot position (SCFP) and (2) the effect of comfortable and standardized foot position (SFP) on plantar pressure and stabilometric parameters. Stabilometry was conducted on twenty healthy subjects in terms of SCFP and SFP. Correlation between AMs and BFMs in SCFP was investigated via Pearson’s analysis. Data variability was assessed using the coefficient of variation, and statistical differences between SCFP and SFP were evaluated via the Wilcoxon test. No correlation was found between AMs and BFMs. Subjects placed their feet nearly parallel in SCFP with a wider inter-heel distance. The variability of plantar pressure parameters was greater in SFP. A lower foot contact area on the right side and higher plantar pressures in the left midfoot region (p-value < 0.05) were found in SFP as compensatory foot adaptations. According to the present study, a comfortable foot position allows for the reduction in postural stability and plantar pressure parameter variability. This position may help improve statistical power when investigating statistical differences between conditions in stabilometry.