The conductance behavior of magnesium, calcium, strontium, barium, copper, and silver perchlorates and their complexes with seven crown ethers have been studied in 20 mass % propylene carbonate + ethylene carbonate. The conductance studies indicate 1:1 complex formation between the metal ion and crown ether. For the alkaline earth metal ions, the order of stability constants with all crown ethers is found to be Mg(II) > Ca(II) > Sr(II) > Ba(II). The limiting ionic conductivities of metal ions and the complexed metal ions are also reported. In addition, complexation studies of Cu(II) and Ag(I) were carried out by potentiometry and voltammetry to compare the results with those obtained by conductivity measurements, which were found to be in good agreement with each other.