The minimal local spread of papillary thyroid cancer (PTC) involves destruction of the thyroid capsule by the tumor and spread of the latter to the muscles of the anterior surface of the thyroid gland. Objective — to evaluate the informative value of ultrasound in the preoperative diagnosis of PTC invasion into the capsule and the neck muscles lying adjacent to the anterior thyroid surface. Subject and methods. The investigation enrolled 85 patients with PTC. The status of the anterior thyroid capsule was evaluated using two methods: ultrasonography and histological examination and, by taking into account the influence of the following clinical and ultrasound signs: sex, age, the presence of a capsule in the tumor, tumor sizes, echogenicity, echostructure, outlines, borders, and shape. B-mode ultrasonography was performed using a Sonoline Antares scanner («Siemens», Germany) equipped with a linear-array transducer of 7—11.5 MHz. Parametric and nonparametric methods for data processing were applied. The SPSS statistical package was used. Results. The sensitivity, specificity, and accuracy of ultrasonography in assessing the destruction of the thyroid capsule were 73, 85, and 77%, respectively; the positive and negative predictive results were 88 and 67%, respectively. A relationship was found between the encapsulated and non-encapsulated nature of a tumor and the destruction of the anterior thyroid capsule (histological findings). No impact of sex or age on the status of the capsule was established. Ultrasonography revealed a correlation of the shape, borders, outlines with the status of the capsule. Conclusion. Ultrasound imaging enables the preoperative diagnosis of tumor spread in the muscles adjacent to the anterior surface in 100% of cases; however, the diagnosis of local capsule destruction needs further analysis.