Background: In health care children often undergo diagnostic and therapeutic painful procedures. Venous sampling, lumbar puncture (back fluid test), needle insertion into venous port, and redressing of wounds are some examples that children may be exposed to. There are several methods to alleviate procedure-related pain, such as general anesthesia and local anesthesia. Objective: The purpose of this study was to map if nitrous oxide administration in painful procedures such as lumbar puncture, needle insertion into venous port, intramuscular injections and gastrostomy button exchange, provides adequate pain relief and sedation and reduces anxiety and fear during these procedures. Method: A total of 92 protocols were reviewed in terms of evaluating the children´s experience of pain, anxiety and fear before and after the painful procedure. The children were divided into groups according to procedure. The study has descriptive, quantitative and retrospective design. Results: The study shows that nitrous oxide can be a good method to reduce experience of pain, anxiety and fear during painful procedures in children with cancer. In painful procedures where the pain remains after the procedure is completed, it has become clear that further pain alleviation may be needed. Most of the children were prepared to use nitrogen oxide in forthcoming painful procedures. Conclusion: Nitrous oxide is an alternative in all types of procedure-related pain. The results show, that nitrous oxide is not suitable for all children and that some procedures may need supplementary pain relief afterwards.