AIM: This study aimed to analyze functionality of sucking and swallowing in preterm and low birth weight premature infants by assessing presence and effectiveness. Because of immaturity of organs and functions, premature infants may require speech therapist care. CASE REPORT: The evaluation of the speech therapist in the neonatal nursery begins with an in-depth survey of the history of the premature infants. Data are raised concerning the history of pregnancy and delivery; gestational age, birth weight, and Apgar score; clinical complications in the postnatal period together with medication used, need for mechanical ventilation, and length of stay on the unit; and type, form, and amount of prescribed power (Rocha and Delgado, 2006). We reviewed the medical data from 30 preterm and low birth weight premature infants born in a public hospital in São Paulo from 2010 through 2011. We verified that the older premature infants had greater weight and showed rapid improvement. Only 15% of premature infants required gastrostomy. The most common manifestations encountered during sucking and swallowing stimulation were crying, pathological reflexes, alertness, and average force during sucking. CONCLUSION: The neonatal speech therapist is extremely important for stimulation and rehabilitation of premature infants with difficulty sucking and swallowing, which is of paramount importance to sensory-motor development.