The present study conducted an experimental investigation of the nucleate pool boiling heat transfer from horizontal copper tubes submerged in saturated R-600a and distilled water. The tubes are incorporated with a porous copper layer lined internally. Effects of heat flux, saturation pressure of both R-600a and distilled water, thermophysical properties of the boiling fluid, and the porous layer thickness and condition (dry or wet) on the boiling characteristics and heat transfer coefficients are the major studied parameters. The results confirmed that, for a given saturation pressure and heat flux, the boiling heat transfer coefficients of the wet porous matrix are consistently higher than those of the dry porous matrix. Also, the results confirmed that the nucleate pool boiling heat transfer coefficients for R-600a are consistently higher than those of distilled water. More attention is directed to correlate the experimental data of heat transfer coefficient, heat flux, and excess temperature to predict the thermal performance of this mode of heat transfer. Good agreements were obtained between the present experimental data and the available published data.