Secondary headache is a symptom of an underlying disease. Infective endocarditis (IE) is a serious infection of the heart tissue. Herein, we present a rare case of IE, with a secondary headache. The patient presented with persistent headache, fever of 39°C, myalgia, and painful erythema of the plantar surface of the foot. The headache progressively worsened over a few weeks. She was diagnosed with secondary headache, and sepsis was suspected. Blood culture revealed the presence of Streptococcus viridans, leading to a diagnosis of IE. Postoperatively, the patient recuperated without any complications. Headaches can be secondary to other conditions. Therefore, comprehensive assessment and accurate diagnosis are essential. Dentists must be aware that headache is a concomitant symptom of IE.