Analysis of Langmuir probe data by using the parametrization of Laframboise’s numerical results was performed to characterize high density plasmas (argon or deuterium discharges) in terms of plasma parameters such as plasma density and electron temperature. The use of parameterizing Laframboise’s results was found to readily extract the plasma parameters for arbitrary ratios of probe radius to Debye length in high density plasmas. It was observed that the electron temperature increased with decreasing gas pressure, and was nearly constant with power in both argon and deuterium plasmas. The plasma density increased with both power and pressure in both argon and deuterium plasmas. Over the power and pressure ranges used in this work, the plasma density in deuterium plasmas was found to be an order of magnitude lower than that in argon plasmas. A simulation study showed good agreement of predicted electron temperature and plasma density with experimental results for argon plasmas.