Measurements of the electrical resistanceRof polycrystalline samples of Bi1.6Pb0.4Sr2Ca2Cu3OYwith the 108‐K superconducting phase show that the Aslamazov–Larkin (AL) two‐dimensional paraconductivity corrections are observable in the vicinity of the mean‐field theory transition temperatureT0C. The effective thickness,d≊23 A˚, of the superconducting electronic sheet as found from the zero field data is comparable to thea,b‐plane separation. This result agrees well with the recent single‐crystal data. The data for magnetic fields up to 1.5 T also show paraconductivity effects.T0C(H) is found to decrease as a function of increasing magnetic fieldH; this result agrees with the prediction of the AL model.