Introduction: Amyloidosis is a rare clinical disorder caused by extracellular deposition of insoluble fibrils known as amyloid leading to organ damage. When cardiac involvement and heart failure are present it carries a poor prognostic if left untreated, with a median survival of 6 months. Methods: A 58 years old female presented for rest dyspnea and reduced effort capacity in the last 4 month. She had a diagnostic of heart failure with preserved ejection fraction prior with poor response to therapy. The patient observed easy bruising in the last year. Clinical examination showed macroglossia, pupuric rash at the level of both arms, signs of systemic and pulmonary congestion, regular heart sound with a rate of 145 beats per minute, arterial blood pressure of 110/80 mm Hg and S3 gallop. The ECG showed atrial flutter, reduced voltage in the limb leads and ST-T abnormalities. Biological tests showed elevated creatinine level and hypoalbuminemia. Urine analysis: proteinuria of nephrotic range. Results: The cardiac ultrasound examination showed nondilated left ventricle with concentric hypertrophy, mild systolic dysfunction, important longitudinal dysfunction and a restrictive diastolic pattern. We suspected an infiltrative cardiomyopathy and referred the patient to a nephrology clinic for histological confirmation. The renal biopsy showed dense amyloid deposits, immunofluorescence positive for lambda chains. Bone marrow biopsy excluded multiple myeloma. The serum determination revealed increased levels of λ and κ chains with κ: λ ratio of 0.32. The positive diagnosis of systemic amyloidosis AL type was made. She received therapy for heart failure and dexamethasone and melphalan. The patient is still alive at the time of concluding this article, at 6 month from diagnostic. Conclusions: This case report underlines the importance of echocardiography, in conjunction with clinical and electrocardiographic findings in making a correct diagnosis and in avoiding any unnecessary tests that can delay giving the patient the correct therapy. Another message is to keep a high index of suspicion for a rare etiology of heart failure – cardiac amyloidosis.