Despite the fact that breastfeeding (BF) remains the simplest, least expensive and healthiest feeding method for infants, it prevalence is reported to has remains low worldwide. This therefore raises a question on what might be responsible for this low practice. No doubt lack of knowledge is the first considered variable. In view of this, this study investigates the level of acceptance and practice of exclusive breastfeeding (EBF) among working class mothers in the nursing service known to have knowledge. The nursing services at the Irrua Specialist Teaching Hospital (ISTH), Irrua in Nigeria forms the targeted population. The study involves 460 mothers in the twenty wards/units of ISTH nursing services, among which 100 were randomly selected to participate. Using a self developed questionnaire data was collected to access the objective of this study. Results showed that only 75% accepted while 23.75% practice EBF. Their claims for this low practice level were time and nature of work, and lack of crèche in work place. Conclusively, mothers in the nursing service do not practice EBF, and hence the low prevalence observed and this will remain so; as they cannot promote what they don’t practice. Based on the findings from this study, it was deduced that EBF can be promoted if working class nursing service mothers are given flexible working hours and crèche are established in hospitals. This will increase the practice of EBF as nurses can begin to spread the importance during prenatal care.