Purpose: The aim of this study was to investigate relationship between the angle of the first metatarsophalangeal joint (1st MPJ) and the dimensions of the abductor hallucis; dorso-plantar (DP) thickness, medio-lateral (ML) width, and cross-sectional area (CSA), in subjects with and without hallux valgus. Methods: Sixty feet, mean (SD) age of 22.5 (2.1) years old, were included in this study (hallux valgus = 30; control = 30). An X-ray device was used for measurement of the angle of the 1st MPJ, and an ultrasound system was used for determination of mean (SD) DP thickness, ML width, and CSA of the abductor hallucis muscle in each foot from three trials. Results: The results showed the DP thickness, ML width, and CSA of the abductor hallucis did not differ significantly between subjects with and without hallux valgus. In addition, the correlations between the angle of the 1st MPJ and DP thickness, ML width, and CSA of the abductor hallucis showed poor correlation (Pearson r=-0.09, -0.20, and -0.18, respectively). Conclusion: Based on these findings, we speculate that morphological changes to the abductor hallucis muscle cannot be representative of the angle of the 1st MPJ, and also cannot be used in differentiation between subjects with and without hallux valgus.