In 2011, the Malawi Ministry of Health (MOH) implemented an innovative approach (called "Option B+"), in which all HIV-infected pregnant and breastfeeding women are eligible for lifelong antiretroviral therapy (ART) regardless of CD4 count. Since that time, several countries have adopted the Option B+ policy. Using data collected through routine program supervision, this report is the first to summarize Malawi's experience implementing Option B+ under the direction of the MOH and supported by the Office of the Global AIDS Coordinator through the President's Emergency Plan for AIDS Relief (PEPFAR). In Malawi, the number of pregnant and breastfeeding women started on ART per quarter increased by 748%, from 1,257 in the second quarter of 2011 (before Option B+ implementation) to 10,663 in the third quarter of 2012 (1 year after implementation). Of the 2,949 women who started ART under Option B+ in the third quarter of 2011 and did not transfer care, 2,267 (77%) continue to receive ART at 12 months; this retention rate is similar to the rate for all adults in the national program. Option B+ is an important innovation that could accelerate progress in Malawi and other countries toward the goal of eliminating mother-to-child transmission of HIV worldwide.