Detailed experiments, encompassing per-tube heat-transfer measurements and rowby- row pressure measurements, were performed to investigate the response of a tube bank to maldistribution of the flow at the inlet cross section. The maldistribution was created by a partial blockage of the inlet section. Baseline experiments for uniformly distributed inlet flow were also carried out. The experiments spanned an order of magnitude range in the Reynolds number. On the whole, the inlet-section flow maldistribution tends to enhance the heat transfer at a given Reynolds number, with an accompanying additional pressure drop of about 2 1/2 velocity heads. Enhancements in the 30-40percent range are encountered in the first several rows in the corridor downstream of the unblocked portion of the inlet section. Reductions (up to 50percent) are confined to a narrow alley behind the blockage. Ten-percent maldistribution-related effects persist to the seventh row, while effects at the 5 percent level occur at least as far downstream as the twelfth row.