Poverty condemns half of humanity to cook with solid fuels on inefficient stoves. Smoke in homes from these cook stoves is the fourth greatest risk factor for death and disease in the world’s poorest countries and is linked to 1.6 million deaths per year. Yet the international community has largely neglected it. Women and children are most at risk from the killer in the kitchen, as they spend considerable time around the cooking fire. Reducing indoor air pollution across the developing world would contribute significantly to achieving the internationally agreed Millennium Development Goals, in particular the aim to reduce child mortality by two-thirds by 2015.