The recovery of palladium(II) from acidic aqueous solutions and sea water using 4-phenylthiosemicarbazide (HPTS) and oleic acid surfactant (HOL) has been studied by ionic flotation. Hydrogen ion concentration, foreign ions, temperature and reagent concentrations have been investigated for attaining the maximum efficiency of palladium(II) flotation. HPTS is used to develop a rapid and sensitive method for the spectrophotometric microdetermination of Pd(II). Various analytical parameters have been evaluated. Beer's law is obeyed over 2.0–14.5 ppm concentration range. The molar absorptivity of the formed 1:1 species is 0.49 x 104L mol−1cm−1at 300 nm. The ligand protonation constant and the stability constants of its complexes with Pd(II) have been determined potentiometrically. The method is successfully applied to determine directly the added Pd(II) to sea water without flotation. Square-planar geometry was proposed for the isolated solid complex. Also, the flotation mechanism is suggested.