This writing aims to examine the fundamental problems, namely the notion of buying and selling bai'ul wafa ', and the view of Islamic law on buying and selling (bai' wafa '). The results of the writing show that the practice of buying and selling bai'ul wafa ', which is in the community is buying and selling by means of credit, and the provision is done by paying down and installments every month when the payment due date, where the company makes it easy for every consumer for consumers is a major factor to attract buyers to buy products offered by the company, while from consumers one of them is the needs of customers who are urgent but not enough money. Furthermore, the view of Islamic law on buying and selling (bai 'wafa'). Islam allows wafa sale, because the buyer must fulfill his promise between the seller, this is done in the initial agreement of the transaction, while this transaction is included in the sale and purchase trust and mutual trust, because the merchandise that has been purchased becomes a mandate for the buyer to return to the seller if the seller returns the money, and the buyer may not sell the item to another person, other than returning it to the seller.