The pure-component parameters of the Perturbed Chain Polar-Statistical Associating Fluid Theory (PCP-SAFT) equation of state are usually fitted to experimental data over broad temperature ranges. Against a background of limited experimental data, this article examines the amount and type of experimental data that are minimally required for safe parameter estimation. For nonassociating components, a minimal data set containing three data points is sufficient. For associating components, five data points are sufficient. The influence of vapor-pressure data on parameter estimation and the modeling results is larger than that of liquid-volume data. The temperature ranges of the experimental data can be chosen to be as small as S K for all of the data, except for the vapor pressures of associating components. These data require a range of at least 20 K. Application of the parameters fitted to the minimal experimental data set led to convincing results for the modeling of pure-component properties and binary mixtures.