An increasing number of criminal court cases have seen psychologists present their findings as evidence after conducting experiments and surveys to evaluate the credibility of witnesses’ statements and suspects’ false confessions. Courts, however, have not always welcomed psychological findings. As some courts have not affirmed the value of these findings in some well-known cases, some researchers suggest that courts have little trust in psychological findings. To consider the validity of this suggestion, we conducted a quantitative investigation of the courts’ decision-making processes when presented with psychological findings in 50 criminal cases. The results showed that most of the courts’ judgments involving psychological findings were negative, and that the reasoning for the judgments could be classified into nine categories. The most common reasons were related to the methodological flaws used to derive the psychological findings.