A 53-year-old man was admitted to the hospital with a diagnosis of cellulitis and osteomyelitis. Twenty-four days after the initiation of daptomycin and sulbactam/ampicillin, he developed a fever and pulmonary infiltration. Bronchoalveolar lavage revealed a high number of eosinophils, while an intracutaneous test revealed positivity for daptomycin. The patient improved after discontinuing antimicrobial therapy. The plasma daptomycin minimum concentration (Cmin) was elevated (27.4 μg/mL), but plasma protein binding of daptomycin was low (87.8%). Although the pathophysiology of eosinophilic pneumonia remains unclear, antigenic stimulation due to daptomycin accumulation in the alveoli may have caused continuous immune activation.