A nematic side-chain liquid-crystalline polymer (SCLCP) was synthesized by grafting a liquid-crystalline monomer, 6-[(4-cyano-4'-biphenyl)oxy]hexanoic acid (5CN-COOH), onto a nearly mono-disperse hydroxylated polyisoprene. The linear dynamic viscoelasticity, steady shear flow, transient and intermittent shear flows, and stress relaxation of the SCLCP in the nematic state were investigated. For comparison, the rheological behavior of a main-chain liquid-crystalline polymer (MCLCP) was also investigated. Similarities and dissimilarities in the rheological behavior between the SCLCP and MCLCP are presented. Some of the important similarities observed are as follows. Upon start-up of shear flow, both SCLCP and MCLCP exhibited a very large overshoot peak of first normal stress difference (N-1(+)) and shear stress (e). The values of first normal stress difference in steady shear flow were positive in both SCLCP and MCLCP over the entire range of shear rates tested. Some of the important dissimilarities observed are as follows. The steady-state shear viscosity (17) of the SCLCP exhibited a Newtonian behavior at shear rates as low as 0.01 s(-1) followed by a shear-thinning behavior at higher shear rates, similar to ordinary flexible polymers, whereas the 17 of the MCLCP exhibited a shear-thinning behavior at low shear rates followed by a Newtonian region at intermediate shear rates and then another shear-thinning behavior at higher shear rates. During intermittent shear flow that was initiated after a rest for 1 h after cessation of steady shear flow, both N-1(+) and sigma(+) of the SCLCP exhibited a large overshoot peak, the magnitude of which was almost the same As that upon start-up of shear flow, whereas the magnitude of the overshoot peak in both N-1(+) and sigma(+) of the MCLCP during intermittent shear flow was much smaller than that upon start-up of shear flow. Upon cessation of steady shear flow, the dynamic storage and loss moduli (G' and G"), which were monitored at a very low angular frequency, of the SCLCP increased initially very rapidly and then leveled off within ca. 40 min, whereas the G' and G" of the MCLCP did not level off in the same period. Upon cessation of steady shear flow, both shear stress and first normal stress difference of the SCLCP relaxed much faster than those of the MCLCP did.