The article analyses the image of a seashell as a part of poetry and prose of Sofia de Mello Breyner Andresen, one of the key-figures of the 20th century Portuguese literature. The research was carried out using the methods of contextual, stylistic and semantic analysis. The results of the study indicate that the image of a seashell occupies a significant place in the work of Sophia de Mello due to a wide range of meanings associated with it. In poetry and prose of the writer, the shell is presented not only as a detail of the seascape, but also as a symbol of harmony, poetry, soul and the manifestation of the divine in the real world.