Low-rate dynamic contact angles on poly(t-butyl methacrylate) (PtBMA) were measured by an automated axisymmetric drop shape analysis profile (ADSA-P). The solid surface tension of PtBMA is calculated to be 18.1 mJ/m(2), with a 95% confidence limit of +/-0.6 mJ/m(2). This value was compared to previous results with different homopolymeric polymethacrylates [poly(methyl methacrylate) (PMMA), poly(ethyl methacrylate) (PEMA), and poly(n-butyl methacrylate) (PnBMA)] and with copolymeric polymethacrylates {poly(methyl methacrylate/ethyl methacrylate, 30/70) [P(MMA/EMA, 30/70)] and poly(methyl methacrylate/n-butyl methacrylate) [P(MMA/nBMA)]}. It was found that increasing length and size of the alkyl side chain decrease the solid surface tension, as expected. Comparison with pure alkyl surfaces suggests that the surface tension of PtBMA is dominated by the very hydrophobic t-butyl group.