Yellow nail syndrome (YNS) is a rare disorder initially described in 1964. It is characterized by a classical triad: yellow nails, lymphedema, and respiratory manifestations. We present a 71-year-old woman who presented with progressive dyspnea. Medical history includes hypertension treated with amlodipine. Examination showed bilateral lower extremity non-pitting edema, yellowish discoloration of nails, and bilateral pleural effusion. Thoracentesis demonstrated chylous effusion. The presumptive diagnosis was YNS. Assuming amlodipine as a cause of interstitial edema, it was stopped, and the symptoms improved gradually. After two months, amlodipine was restarted externally, and the dyspnea relapsed. Amlodipine was discontinued again. After two years of amlodipine cessation, the patient remained well without symptoms. The progression and resolution of symptoms point to amlodipine as a suggested cause of YNS. Paying attention to the prescribed drugs was the key to diagnosing and resolving serious complications.