Labor is one of the painful conditions that are considered to be the most intense and stressful experiences. In the last decades, changes have occurred in the obstetric expectations and in their care. In developed countries, the number of women requesting labor analgesia is increasing, and in some communities, an effective pain relief for childbirth is in great demand. As it is cheap, simple to use and readily available, systemic pethidine is widely used for relief of labor pain. Use of parental opioids was found to be between 39% and 56% in various hospital obstetrics units, in the United States. Systemic opioids lead to some adverse effects on both mother and baby. Including dysphoria, sedation, respiratory depression, nausea and vomiting and delayed gastric emptying for the mother. Self-administered 50% nitrous oxide is an effective and safe form of analgesia, which has been used by many emergency medical services for many years. Nitrous oxide is an odorless, tasteless, inhaled analgesic, and it found to be an effective analgesia for many women while also being safe for the mothers and babies.14 now a day, nitrous oxide is widely used in many countries for relieving labor pain.