Triphenylacetic acid is isomorphous with the published structure of triphenylchloromethane (I). It crystallizes in the trigonal system, space group P3, witha=b=14.105(3)Å,c=13.121(2)ÅV=2261(1)Å3,Z=6 at 175K. The structure was solved by direct methods and refined toR(F0)=0.062. We determined the structures for two triclinic polymorphs of triphenylchloromethane,IIandIII. The three forms were obtained from pentane evaporated at room temperature. PhasesIandIIIwere isolated from particular solvent systems. Crystal data (II): triclinic system, space group P3, witha=13.028(1)Å,b=13.559(2)Å,c=13.969(3)Å, α=117.67(1)°, β=92.67(1)°, γ=91.43(1)°,V=2179.9Å3,Z=6 at 228K. The structure was solved by direct methods and refined toR(F0)=0.045. Crystal data (III): triclinic system, space group P3, witha=14.1562(4)Å,b=21.3190(7)Å,c=13.0654(5)Å, α=99.92(3)°, β=92.68(3)°, γ=106.15(2)°,V=3712(2)Å3,Z=10 at 248K. The structure was solved by direct methods and refined toR(Fo)=0.064. A batch of crystals from pentane showed three peaks in the DSC thermogram at 99°C (III), 108°C (II), and 111°C (I). PhaseIIImelts without being transformed to phaseIIor phaseI. PhaseIIcould not be isolated for calorimetric studies.