Lumbar puncture (LP) is an important procedure both for diagnostic and therapeutic purposes. In Kelantan, Malaysia, on many occasions consent for this procedure is not granted by patients or guardians. The aim of this study was to find out the factors that influence the decision to grant or refuse the consent for LP. This was a cross-sectional study in which 86 parents (who agreed or refused to give consent for LP on their child) were interviewed by using a standard questionnaire. A scoring system was used to assess their knowledge about the purpose and technique of the procedure. Consent for LP was granted in 23 and refused in 27 children. The refusal rate was significantly higher when family members other than parents made the decision. The factors which did not play a statistically significant role in decision-making included: age of the child and parents; gender of the patient; number of children in the family; patient's birth order among the siblings; place of residence; monthly income of the family; parents' level of education; and number of days after admission when LP was requested. The factors that positively influenced the decision to give consent included knowledge about the purpose of LP and underlying disease. In order to receive positive consent for LP it is concluded that the parents/guardians and other family members who may influence the decision-making should be explained the role of LP in (1) making diagnosis and (2) choosing right antibiotics for treatment. They should also be informed about the side-effects of antibiotics, which may be used unnecessarily in unconfirmed cases of central nervous system infections.