With a view to investigating further the surface tensions of (a hydrocarbon + a perfluorocarbon) in which neither component is aliphatic-and thus open to chain-flexibility effects-or aromatic-and thus dominated,by specific interactions, we have studied the orthobaric (gas + liquid) surface tension of methylcyclohexane at temperatures from 293 K to 338 K, of tetradecafluoromethylcyclohexane from 298 K to 338 K, and of their mixture across the full composition range at temperatures from 320 K to 335 K close to the upper critical solution temperature, T(UCS) = 319.262 K. The mixture is normal in the sense that the more volatile component, tetradecafluoromethylcyclohexane, has the lower surface tension. Reflecting the occurrence of marked positive deviations from bulk-phase ideality, emphasized by the occurrence of positive azeotropy, the mixture displays marked negative deviations from surface ideality, just sufficient to yield aneotropy or surface azeotropy a few kelvins above T(UCS). Near T(UCS) the isotherms display the inflection characteristic of the prediction of Widom’s theory of surface tensions at the non-critical interface of a mixture close to an upper critical end point. The total surface segregation, although positive across the entire mole-fraction range, shows the signature of both the critical end point and the azeotrope.