One of the most important literary currents that was strengthened in Iran's poetry in the 1950s following the coup d'etat of August 19, 1953 was romanticism that prevailed the field of poetry. Dark themes became commonplace with extreme and unprecedented emotions; themes that diverted this version of romanticism from the essence of lyric which often meant that the poets either speak of death of love, or brought it down to its lowest level. These poems, belonging to a current known as dark romanticism, reflect themes such as thoughts of death, feeling of being cursed, rebellion, declaring sin, disbelief and immorality, Satanism, despair, and so on. Some scholars have defined these poems as lyrical romanticism, while lyrical and dark romanticism have fundamental differences, including in their world views, themes and contextual factors. In this article, after examining the nature of dark romanticism and its sentimentalism in Iran, common dark themes in the poems of some poets such as Nader Naderpour, Nosrat Rahmani, Karo, Hasan Honarmandi, Hamid Mosadegh and Forough Farrokhzad are evaluated. The results of the study shows that, with regard to the focus on themes such as thinking of death, disappointment and despair, rebellion and being cursed, fear, satanism, addiction and inebriation, and opposing the ethics and social norms, disbelief and denunciation of love in the poetry of dark romanticism, these poems cannot be identified as lyrical romanticism.Accordingly, romantic and sensual poetry of the 1950s was divided into two categories which is lyrical and non-lyrical romanticism.