AIM: In this study, we investigated the sensitivity of TrichoScan, a computer-based phototrichogram, in the evaluation of diffuse hair loss in women and the relationship between iron deficiency anemia and hair loss. MATERIALS AND METHODS: We recruited 100 female patients with diffuse hair loss. In all of the patients, a 1-cm2 area of hair located in a temporoparietal region was shortened to 0.5 mm. The shaved scalp regions were stained with black dye. The subject then waited for 12 min. Subsequently, pictures of these regions were taken with a videodermoscope and analyzed with the TrichoScan software program. RESULTS: The ferritin levels were markedly low in these groups. The ratio of anagen was highest in the telogen effluvium (TE) mild group, followed by the TE severe group, and was lowest in the androgenetic alopecia (AGA) group (P <0.05). The ratio of telogen was markedly higher in the AGA group, and the difference was statistically significant when compared with the other 2 groups (P < 0.05). CONCLUSION: The hair analysis results with the TrichoScan software were satisfactory and the results were consistent with the clinical diagnosis. In particular, the use of TrichoScan was very successful in the differentiation between AGA and TE.