In 1893 and 1903, two volumes of Frege’s most important work Grundegezte der Arithmetik were published. This period can be called the peak of Frege’s logicism. Although the subject of truth in Frege’s logical and philosophical works has been repeatedly investigated there is a lack of studies on his view in this period, especially in the Polish literature.In this article, therefore, I carry out the following research task: to collect and order Frege’s statements about the truth during the period of publishing two volumes of Grundegezte der Arithmetik. I will refer to texts published during Frege’s life, published posthumously and his correspondence. Particularly noteworthy are: Grundegezte der Arithmetik and the unpublished Logik (1897–1898). That iswhy separate sections are devoted to these two items, and remarks on truth from other texts are grouped thematically: the problem of antinomy, geometry, expression of generality, and others. The subject of truth appears here in relation to logic, philosophy of language, philosophy of logic, philosophy of mathematics and ontology.