The book “Riyadhus Sholihin” is a monumental work written by one of the great scholars who has a high reputation among the Muslims, namely Imam Nawawi. Although the main topic of the book is about encouragement and warningsand also purification of the self, the book also includes themes of faith and oneness of Allah conceptualized by the author in separate chapters accompanied by the arguments from the Qur’an and hadiths, including the Chapters Talqin “al-Muhtadhar” LaaIlaahaIllallah. Then, how is the correlation of the hadiths that he presented with this chapter and with the tawhid uluhiyyah ‘oneness of worship’? This qualitative research paper attempts to answer these questions using the library research method with a content analysis approach. The discussion of this paper is divided into several sub-sections: introduction, brief biography of Imam Nawawi, the meaning of tawhid uluhiyyah, the chapter Talqin and the correlation of the chapter and its arguments with tauhid uluhiyyah, and conclusions, including the following conclusions: (1) Riyadhus Sholihin is not a mere hadith book that discusses the themes of encouragement and warnings and purification of the self, but also contains theme on faith, (2) Imam Nawawi’s foresight in conceptualizing the chapters of the book and selecting related arguments withinthem, (3) The correlation between chapter Talqin "al-Muhtadhar" Laa Ilaaha Illallah and tawhid uluhiyyah is obvious, because LaaIlaahaIllallah is a tawhid propositionwhich content is the obligation to give worship only to Allah, that is the essence of tawhid uluhiyyah, (4) The correlation of two hadiths which arestated in the chapter Talqin "alh-Muhtadhar" Laa Ilaaha Illallah with tawhid uluhiyyahis very firm and clear.