This study aimed at identifying the multinational companies legally through searching about the legal concept of Multinational Companies and their most important characteristics. Multinational companies are group of companies affiliated to a parent company; yet it is legally independent from it. The study identified also the most important cases that lead to the liability of multinational companies towards the debts of their affiliate company through answering the following questions: 1- What is the definition of multinational company? What are their elements and characteristics? 2- What are the cases in which the parent company would be held liable for the debts of their affiliate companies? 3. What are the consequences resulting from the liability of the parent company for the debts of their affiliate companies? We have addressed these subjects in three chapters: The introductory chapter has been dedicated to the legal concept of Multinational companies in sections. In the first section, we tackled the nature of multinational companies; whereas we tackled in the second section the characteristics of multinational companies. The first chapter has been dedicated to tackle the liability of the parent company as an administrator for the company; whereas the second section addresses the liability of the parent company according to the rules of tort. Then we dedicated the second chapter for the liability of the parent company in case of fictitious affiliation in two sections. The first section tackles the case of fictitious affiliation between a group of Multinational Companies; whereas the second section addresses the case of mixing between financial liabilities.