Background Increasing the coverage of key maternal, newborn, and child health interventions is essential if Millennium Development Goals (MDG) 4 and 5 are to be reached. We have assessed equity and trends in coverage rates of a key set of interventions through a summary index, to provide overall insight into past performance and progress perspectives. Methods Data from household surveys from 54 countries in the Countdown to 2015 for Maternal, Newborn and Child Survival initiative during 1990-2006 were used to compute an aggregate coverage index based on four intervention areas: family planning, maternal and newborn care, immunisation, and treatment of sick children. The four areas were given equal weight in the computation of the index. Standard measures were applied to assess current levels and trends in the coverage gap measure by wealth quintile. Findings The overall size of the coverage gap ranged from less than 20% in Tajikistan and Peru to over 70% in Ethiopia and Chad, with a mean of 43% for the most recent surveys in the 54 countries. Large intracountry diff erences were noted, with a country mean coverage gap of 54% for the poorest quintiles of the population and 29% for the wealthiest. Diff erences between the poorest and the wealthiest were largest for the maternal and newborn health intervention area and smallest for immunisation. In 40 countries with more than one survey, the coverage gap had decreased by an average of 0.9 percentage points per year since the early 1990s. Declines greater than 2 percentage points per year were seen in only three countries after 1995: Cambodia, Mozambique, and Nepal. Country inequity patterns were remarkably persistant over time, with only gradual changes from top inequity (disproportionately smaller gap for the wealthiest) in countries with coverage gaps exceeding 40%, to linear patterns and bottom inequity (disproportionately greater gap for the poorest) in surveys with gaps below 40%. Interpretation Despite most Countdown countries having made gradual progress since 1990, coverage gaps for key interventions remain wide and, in most such countries, the pace of decline needs to be more than doubled to reach levels of coverage of these and other interventions needed in the context of MDG 4 and 5. In general, in-country patterns of inequality are consistant and change only gradually if at all, which has implications for the targeting of interventions.