Neutropenia can be caused by a variety of congenital and acquired factors, with Chemotherapy-induced myelosuppression being the most common cause. Neutropenia significantly affects oral health, leading to the manifestation of oral lesions such as ulcers, fungal and viral infections, and mucositis. This study aims to investigate oral lesions in patients with hematological malignancies who developed neutropenia after chemotherapy. This cross-sectional study included 50 patients with hematological malignancies. The participants were divided into 2 groups: the first group consisted of 25 patients with hematological malignancies who developed chemotherapy-induced neutropenia and the second group consisted of 25 patients with hematological malignancies who did not develop chemotherapy-induced neutropenia. Patients were assigned to one of the groups based on the absolute neutrophil count (ANC). Full oral clinical examination was performed to determine the presence of oral lesions. In the Chemotherapy-Induced Neutropenia group, the most common lesion was ulceration, observed in 12 patients (48%). Fungal infections were the second most common, present in 5 patients (20%), followed by viral infections in 4 patients (15%), and mucositis, which occurred in a single patient (4%). A statistically significant association was found between neutropenia and the presence of oral ulcers (P value = .015). In contrast, in the Chemotherapy group, oral changes were less frequent. Fungal infections were the most common, occurring in 4 patients (15%), followed by oral mucositis in 3 patients (12%). Ulceration and viral infections were the least common, each observed in 1 patient (4%). The frequency of various forms of oral ulcers increases with the severity of neutropenia. However, there was no significant increase in other oral lesions in patients with neutropenia.