Immediate breast reconstruction with tissue expander has become an increasingly popular procedure. Complete coverage of the expander by a musculofascial layer provides an additional well-vascularised layer, reducing the rate of possible complications of skin necrosis, prosthesis displacement, and the late capsular contracture. Complete expander coverage can be achieved by a combination of pectoralis major muscle and adjacent thoracic fascia in selected patients. Seventy-five breast mounds in 59 patients were reconstructed, in the first stage a temporary tissue expander inserted immediately after mastectomy and a musculofascial layer composed of the pectoralis major muscle, the serratus anterior fascia, and the superficial pectoral fascia were created to cover the expander. The first stage was followed months later by implant insertion. Minor and major complications were reported in a period of follow-up ranging from 24-42 months (mean 31 months). Complete musculofascial coverage of the tissue expander was a simple and easy to learn technique providing that the patient has a well-formed and intact superficial pectoral and serratus anterior fascia. From a total of 75 breast mounds reconstructed, major complications rate was 4% (overall rate of 19.8%), including major seroma (n = 4), haematoma (n = 1), partial skin loss (n = 3), wound dehiscence (n = 1), major infection (n = 2), severe capsule contracture (n = 1), and expander displacement (n = 3). The serratus anterior fascia and the superficial pectoral fascia flaps can be effectively used as an autologous tissue layer to cover the lower and the lateral aspect of tissue expanders in immediate breast reconstruction after mastectomy.