Prior research has found that unaudited values influence auditors' analytical procedures judgments, including estimates of account balances and investigation decisions. When unaudited values influence account investigations, audit effectiveness could be impaired. Prior studies have not examined whether the extent of influence of unaudited values is reduced when there are indications that client-supplied values may be unreliable, as suggested by psychological theory. Using a between-subjects design, this study examines whether factors affecting reliability of unaudited values (significant accounting system changes or prior material audit adjustments) affect the influence of unaudited values in analytical procedures, and whether the impact of possible reliability problems differs by prior data trend (increasing or decreasing). Participating auditors estimated the actual value of the gross profit percentage, and provided bounds beyond which they would investigate the unaudited value. Results show that unaudited values influenced auditor judgments, except when there was an indication that the data may be unreliable and the unaudited gross profit percentage was increasing from the prior year. When these two conditions combined, the auditors were more conservative in their use of the client-supplied information.