Between 1910 and 1916, he was the Director of special collections at the National Library and also served as Editor of numerous magazines, including the children’s publication Veselushka. Additionally, he served as a war correspondent during World War I.

In 1911, one of his most famous works appeared, The Gerak Family (Bulgarian: Geratsite). It is one of the best-known pieces of Bulgarian literature and deals with a traditional village family experiencing the transition from the simplicity of rurality to the modernization of Bulgarian society, a world in which old time practices founded on family love and dedication to the land start to disappear. His second great work, Earth (Bulgarian: Zemya), was published in 1922. In this book, Pelin created a gallery of characters who identified with the national character and conscience.

From 1924 until 1944, Pelin served as conservator at the Ivan Vazov Museum, all the while continuing to write, mostly for children, and be published. In 1940, he was named President of the Union of Bulgarian Writers.

Earth and The Gerak Family, amongst other works, have been filmed several times (1930 and 1957, and 1958, respectively).

Pelin’s works—poems, short stories and novels—recreated the peasant and countryside atmosphere of the old Bulgaria. His predilection for short stories led him to write many, of which the humouristic Pizho and Penda is perhaps the best known. A genuine realism, with descriptions full of light and color, classify his works. Considered one of the masters of Bulgarian prose, he was also one of the initiators of Bulgarian children’s literature. His tales of Yan Bibiyan and his voyages to the moon still delight today.