Aqueous solubilities Of two C20H14 isomers, triptycene (9,10-o-benzeno-9,10-dihydroanthracene) and 9-phenylanthracene, were measured at temperatures from 313 K to the solute melting point and pressures close to 5 MPa by a dynamic method combined with gas chromatography/mass spectrometry. In addition, aqueous solubilities of 2-methylanthracene and 9, 1 0-dimethylanthracene were also obtained. The curvature of the temperature dependence of triptycene solubility differs distinctly from those for the other solutes. Although no data on aqueous solubilities of the solutes at T > 323.15 K were found in the literature, the results for methylanthracenes at the lower limit of the temperature range of the present measurements compare favorably with previous reports. The activity coefficients of triptycene in saturated aqueous solutions were estimated from the measured solubilities employing two different approximations for the pure solute heat capacity difference Delta C-P2.