Digoxin is widely used in the treatment of congestive heart failure andsome arrhythmias. Digoxin toxicity may occur easily because digoxin has anarrow therapeutic index. This retrospective study was conducted to evaluatethe clinical signs and symptoms of toxic serum digoxin levels in neonates.Medical reports of the neonates who had serum digoxin concentrations >2nanogram/milliliter (ng/ml) were reviewed in terms of patient demographics,serum digoxin concentrations, signs and symptoms of digoxin toxicity, serumdigoxin and electrolyte levels, renal function tests, electrocardiograms,echocardiography, and treatments applied. Digoxin toxic levels were identifiedin the 13 neonates. Of the 13 neonates with digoxin toxic level, 9 (69%)were term and 8 (62%) were female. Twenty-three percent (3/13) ofnewborn infants were symptomatic. Symptomatic patients had statisticallysignificantly higher serum digoxin levels, at 7.76±2.76 (5.4-10.8) ng/ml,than asymptomatic patients, at 3.31±1.09 (2.02-4.95) (p=0.036). Symptomsrelated to toxic digoxin levels were observed in the three neonates withplasma digoxin levels >5 ng/ml. Gastrointestinal and central nervous systemsymptoms were the major clinic findings. Despite high digoxin levels, nodigoxin-related arrhythmia was observed on electrocardiography, other thansinus bradycardia. Two premature neonates were treated with digoxin-specificantibody Fab fragments (DigiFab®) and hypokalemia developed in both ofthem. Our data suggests that symptoms related with digoxin toxic levels wereobserved in neonates with plasma digoxin levels >5 ng/ml. Serum digoxinlevels should be measured in case of signs and symptoms of digoxin toxicityor risk factors for such toxicity.