Opioids are not always available in many developing countries, including those in Latin America. In this study we analyzed the national laws on opioids and other controlled substances from Argentina, Colombia, Costa Rica, Peru, Mexico, and the state of Texas, according to the principles set by the World Health Organization (WHO) and the International Narcotics Control Board (INCB), as well as to the presence of over-regulations regarding their medical and scientific use. The six main principles outlined by WHO and INCB for opioid availability were analyzed by using a total of 17 criteria as shown in Table 3. The result scores ranged from 17/17 (full compliance with all criteria) to 0/17 (non-compliance). Results showed that with the exception of the state of Texas 16/17 (94%), the countries failed to adequately meet the INCB and WHO criteria: Argentina: 7/17 (41%); Colombia: 9 /17 (53%); Costa Rica: 9/17 (53%); Mexico: 4/17 (24%); and Peru: 7/17 (41%). In all 5 Latin American countries, national laws and regulations imposed limits on the number of days allowed for prescription, the potency of the dosage, and the number of doses allowed per day. In all cases, including Texas, there was confusion on the meaning and utilization of the terms physical dependence, psychological dependence, addiction, tolerance and abuse. In total, combining all cases, only 51% of the criteria were met. Additionally, all laws and regulations, especially in Argentina, include over regulations and statements that may further interfere with patient access to opioids. The prescription criteria were fully met by the state of Texas and all five countries. These results indicate that there is need to revise the existing laws and regulations in countries with opioid availability problems, and identify the potential barriers, which may be playing a significant role in the access to adequate treatment. Such review seeks to carefully consider all possible criteria, since partial resolution of legislative articles will not result in increased opioid availability.