Background Undernutrition is associated with an increased risk of death among young children in developing countries. Infant and child nutritional status and mortality were monitored in a rural area of Casamance, Senegal.

Methods Analysis of weight measurements taken at 3–24 months of age during routine growth monitoring in the community's private dispensary 1969–1992 (3912 children, 4642 child-years) and of mortality rates of children estimated from maternal recall for 1960–1985 and yearly census 1985–1995.

Results Between 1960–1964 and 1990–1994, under-5 and child (1–4 years) mortality rates decreased from 312 to 127 and from 201 to 68 per 1000, respectively. About 90% of resident children attended growth monitoring in 1985–1992. Mean weight-for-age was at a minimum at 15 months of age (-1.60 z-scores [SD: 0.95]); the prevalence of underweight was 33.2% (95% CI: 31.5, 34.9). The latter increased significantly over time, both when comparing all years of follow-up (P for trend <0.01) and over three pre-defined time periods (28.6, 34.6, and 35.0% in 1969–1974, 1975–1984, and 1985–1992, respectively, P for trend <0.05). Mean weight-for-age decreased over time in infancy and in the second year of life.

Conclusion No improvement in nutritional status was found among young children 1969–1992 despite a drastic decrease in mortality. Focused public health interventions such as vaccinations and malaria prevention probably did not enhance weight-for-age. Paradoxically, growth monitoring may have been more helpful in improving health than growth.