Policies relating to contraceptive services (population, family planning and reproductive health policies) often receive weak or fluctuating levels of commitment from national policy elites in Southern countries, leading to slow policy evolution and undermining implementation. This is true of Kenya, despite the government's early progress in committing to population and reproductive health policies, and its success in implementing them during the 1980s. This key informant study on family planning policy in Kenya found that policy space contracted, and then began to expand, because of shifts in contextual factors, and because of the actions of different actors. Policy space contracted during the mid-1990s in the context of weakening prioritization of reproductive health in national and international policy agendas, undermining access to contraceptive services and contributing to the stalling of the country's fertility rates. However, during the mid-2000s, champions of family planning within the Kenyan Government bureaucracy played an important role in expanding the policy space through both public and hidden advocacy activities. The case study demonstrates that policy space analysis can provide useful insights into the dynamics of routine policy and programme evolution and the challenge of sustaining support for issues even after they have reached the policy agenda.