Cladribine is an approved drug for the treatment of highly active multiple sclerosis. We report a 28-years-old man with a poor response to previous treatments, elected to treatment with Cladribine. He developed a lichenoid rash two weeks after taking the first and second treatment cycles. This symptom regressed with specific therapy. A lichenoid drug eruption is a rare side effect which can occur following the administration of several different medications, but it has never been described after treatment with oral Cladribine.