This research is directly relevant to the ASEAN Security Community (ASC). One of the fundamental visions is particularly associated with combatting transnational crime and international challenges effectively in a timely manner. This study has three objectives as follows; (1) to explore causes and current situation of crime resulting from cross-border migration from Laos to Thailand due to the establishment of ASEAN community, (2) to deeply analyse immigration and crime trends across Thai-Lao borders, and (3) to propose approaches to preventing the immigration from Laos to Thailand for criminal purposes. In-depth interviews were conducted to gather crucial information from key informants, followed by two focus group discussions. However, the trend of crimes committed by Lao immigrants in Thailand after the inauguration of ASEAN community is inconsistent. Though, the initial hypothesis and public believed that checkpoints for border trade for commodity flows and labour transfers would worsen the issues of drugs and illegal immigration. Research findings indicated that drug-related crime and illegal immigration issues tend to decrease because the opening of ASEAN community allows the Thai and Lao governments to strengthen their international relations. Thus, it can be stated that warm diplomatic relations between countries are the main factor contributing to a successful prevention for transnational crime.