AbstractOptical rotatory dispersion (ORD) and circular dichroism (CD) of poly(L‐lactate) were investigated and were compared with those of optically active oligo(L‐lactate), prepared by the stepwise method. Two‐term DRUDE equation was applied to analyse the ORD curves using n‐π* and π‐π* transition bands as the critical wavelengths, Λ0 and Λ1. No drastic difference in ORD between poly(L‐lactate) and oligo(L‐lactate) was detected in chloroform and dioxane, which suggests that the polymer does not form any special conformation in these solvents. However, in acetonitrile it was found that the value of −A1/A0 (A1 and A0 are constants characteristic of π‐π* and n‐π* transitions of ester chromophores, respectively) of the polymer differed from that of the oligomer (n = 3).