Gilmartin increased the stock price of Merck & Company fourfold during his first four years as head of the company. Gilmartin has focused the company’s research endeavors on therapies which can benefit large populations. He also successfully integrated the acquired Medco into Merck & Company’s corporate culture. Recognizing Gilmartin’s leadership in creating a positive working environment, Fortune ranked Merck & Company as one of the top 10 best companies to work for.