In our previous paper, we proposed a novel screening method that aids the diagnosis of female patients with Graves’ hyperthyroidism via two types of neural networks and the use of routine test data. This method can be applied by non-specialists during physical checkups at a low cost and is expected to lead to rapid referrals for examination and treatment by thyroid specialists; i.e., to improve patients’ QOL. In this report, we investigate whether the screening method is also applicable to males since sex differences exist in routine test data. The values of 14 routine test parameters for 78 subjects with definite diagnoses (31 patients with Graves’ hyperthyroidism and 48 healthy volunteers) were adopted as training data, and 133 individuals who had also undergone the same routine tests at Tohoku University Hospital were screened for Graves’ hyperthyroidism using our method. The present examination of our screening method in males showed its high screening ability with the set of parameters used (low serum creatinine, elevated alkaline phosphatase, and low total cholesterol). It was also found that there is strong multiple correlation between a set of three parameters and serum free thyroxine (FT4) in male patients with Graves’ hyperthyroidism. A formula for FT4 consisting of three parameters was obtained, and this can be utilized in place of the true FT4 value. This result also supports the usefulness of our screening method.