Background: Histone deacetylases (HDACs) are critical epigenetic modulators involved in regulating various molecular mechanisms essential for cell development and growth. Alterations in HDAC activity have been linked to the progression of numerous cancers, including lymphoma. Over the past decade, the FDA has approved several HDAC inhibitors for lymphoma treatment, leading to heightened interest in this emerging class of drugs. Methods: In our research, we developed a novel HDAC inhibitor that exhibits high selectivity for class I HDACs. Results: Our in vitro findings indicate that treating lymphoma/leukemia cells with this inhibitor results in a marked suppression of cell growth and promotes apoptosis, while leaving the cell cycle unaffected. Conclusions: We propose that our new inhibitor, named eimbinostat, holds significant promise as a potential therapeutic agent for the treatment of hematologic malignancies such as lymphoma or leukemia.