INTRODUCTION: Neonatal abstinence syndrome (NAS) refers to a newborn neurological, gastrointestinal and/or respiratory disorder if a newborn was exposed to psychoactive substances in the intrauterine period. NAS is difficult to diagnose due to unreliability of the data on addictive substances use during pregnancy, limited possibilities of the prenatal exposure diagnosis and postnatal substance detection, which all lead to diagnostic dilemmas. OBJECTIVE: The aim of this study was to indicate the problems in patients with early NAS diagnosis in the maternity ward and the importance of clinical presentation used as a guide toward the diagnosis. METHODS: This retrospective study included five term eutrophic newborns with high Apgar score, good adaptation in the first day and with clinical presentation of NAS during the second day of life. The clinical presentation was dominated by irritability, increased wakefulness, increased muscle tone, shrilly crying, tremors, problems with accepting food, tachypnea, subfebrility and hyperhidrosis. Finnegan scale was introduced in order to diagnose NAS and apply the therapy. Single-medication therapy of phenobarbitone was applied in four cases and a combination of phenobarbitone and morphine in one case. For toxicological analysis newborns'urine samples were used. RESULTS: Conditions such as perinatal asphyxia, infection, hunger, polycythemia, hypoglycemia or hypocalcemia were excluded. Finnegan score implied that pharmacological treatment had to be administered. The discrepancy between the NAS anamnesis and toxicological analysis existed. Response to the treatment was positive in all cases. CONCLUSION: NAS is a multisystemic disorder and should be suspected when it is noticed that children exhibit characteristic signs. However, other pathological conditions have to be excluded. Quantification according to the adopted scales for NAS leads toward appropriate treatment and recovery of the newborns.