The contact angle (theta) of water on the surface of various poly(alkyl methacrylate)s was measured in order to obtain a relationship between the chain length of the alkyl group and the surface energy of the polymers, where the alkyl is an n-CnH2n+1 (n = 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, and 20) group and a phytanyl or (3RS,7RS,-11RS)-3,7,11,15-tetramethylhexadecyl group. Generally, the plotting of theta vs alkyl chain length gave a bell-shaped curve to show the maximum theta at a certain poly(alkyl methacrylate). The theta of each polymer, however, varied characteristically with temperature; hence, the polymer providing the maximum theta was altered to another polymer by changing temperature. The complex phenomenon was analyzed by the means of DSC, ESCA, XRD, and RAS IR spectra, etc. of the polymers to reveal that the contact angle was dramatically enhanced when the polymer state was changed to a noncrystalline (melt) state from a crystalline state. In other words, the polymer, which possesses long alkyl groups with random packing, was found to provide a highly hydrophobic surface. Especially, poly(phytanyl methacrylate) was fit to these conditions to express a very large theta (120-125 degrees) over a wide temperature range (10-60 degrees C), being the most hydrophobic hydrocarbon material ever prepared.