The comprehensive development in Saudi Arabia forced the private sector to bring foreign employees to assist in accomplishing this development. The number of foreign employees reached to six million people according to the late statistics. This huge number of people exerted pressure on the public free medical facilities that forced the government to issue a decree that instructs private sector to use private medical facilities for their foreign employees. The private sector dealt with this decree in different ways according to the perception of the company from providing full medical coverage for their employees to providing nothing. This has created a problem to many foreigners in which they have to pay for their medical needs. The government, then, issued a new decree that is the mandatory medical insurance. This decree requires the private sector to provide full medical coverage for their foreign employees. This decree will have an impact on the construction companies (contractors) and the cost of the construction projects. This paper presents results of a study conducted to identify the impact of the mandatory medical insurance on the construction contractors in Saudi Arabia. The methodology used was to prepare a questionnaire that investigates the objectives of this study and distributes it to the contractors. The questionnaire includes many aspects among them the impact of this decree on the company performance and the competition between contractors; how this extra expense being dealt with; and the impact on the employee. The questionnaires were distributed to 150 construction contractors and 90 questionnaires were collected. Results of the study reveal the impact of the mandatory medical insurance on the construction contractors in general and according to their classifications. In addition, the study presents the current practice implemented by contractors to provide medical care for their foreign employees.