Polydiarylsiloxanes and polydialkylsiloxanes, with alkyl groups larger than methyl, have liquid-crystalline states, presumably as the result of a chain-rigidifying effect from steric interactions of the bulky aryl or alkyl groups along the chain. In the first paper of this series, we reported on the thermal behaviour of a number of diarylsiloxane polymers with phenyl and/or p-tolyl substituents, all of which showed liquid-crystalline behaviour at high temperatures. The solution properties of several of the ’mixed’ poly(phenyl/p-tolyl) siloxane polymers have now been investigated in order to characterize their chain stiffness properties and to relate these to the tendency to form a liquid-crystalline state in bulk. The ’mixed’ poly(phenyl/p-tolyl) siloxanes were chosen for investigation since they have a major advantage in experimental convenience over the ’unmixed parent’ polymers, polydiphenylsiloxane and polydi(p-tolyl)siloxane. The former are soluble at room temperature in common solvents, whereas the latter polymers are only soluble at temperatures above 150-degrees-C. The various diarylsiloxane polymers were prepared by anionic polymerization of the cyclic trimers, and the preservation of the triad sequences (absence of ’scrambling’) was confirmed by Si-29 n.m.r. Values of the Mark-Houwink-Sakurada exponent, a, for three different types of poly(phenyl/p-tolyl) siloxanes are essentially equal, at approximately 0.83. This value of the exponent is below the value expected for a rigid chain (a > 1.0) but is above the maximum value expected for a flexible random-coil polymer in a good sol vent (a less-than-or-equal-to 0.8). The shear viscosity of solutions of the mixed poly(phenyl/p-tolyl)siloxane polymers increases monotonically with increasing polymer concentration up to 60 wt%, and does not show an abrupt drop in viscosity above a critical concentration, as is often observed with rigid-rod polymers. This observation, together with the value of the Mark-Houwink-Sakurada exponent, a < 1, indicates that these polymers do not behave in solution as rigid-rod polymers, but most likely as worm-like chains with a relatively large persistence length.