In this study, two extractants, hexakis[(dimethylthiocarbamoyl)oxy]thiacalix[6]arene (1) and tetrakis[(dimethylthiocarbamoyl)oxy]thiacalix[4]arene (2), were synthesized by the reaction of dimethylthiocarbamoyl chloride with p-tert-butylthiacalix[n]arenes (n = 6 and 4) and characterized using H-1 NMR and FT-IR spectroscopies, elemental analysis, and fast-atom-bombardment mass spectrometry (FAB-MS). These compounds were extensively evaluated for the extraction of Pd(II) ions from HCl media and solutions of platinum-group metals from automotive catalyst residues, using various solvents. Compounds 1 and 2 were found to have higher Pd(II)-ion extraction abilities (0.57 and 0.48 g/L, respectively) than the native p-tert-butylthiacalix[6]arene (3) and p-tert-butylthiacalix[4]arene (4) (0.46 and 0.20 g/L, respectively), using 1 mM extractant and 9.4 mM Pd(II)-ion solutions in HCl media. The extractant-Pd(II) complexes were characterized using FT-IR spectroscopy, elemental analysis, XRD, Job's continuous method, and TGA/DTA. Stripping of the Pd(II) ions from the extractants was performed using 1 M thiourea, thereby enabling the reuse of the extractants.