The ecological association of infant mortality rate (IM) with per capita income (PI) and prevalence of adult illiteracy (AI) has been studied using countries as the unit of analysis. A negative association between IM and PI in 1960 and 1982 has been observed (sample correlation coefficient [r] = -.625 and r = -.729, respectively; P less than .05). A correlation between IM and AI has been found for both men and women (r = .827 and r = .855, respectively; P less than .05). The ecological relative risks were 7.43 for men and 5.82 for women (95% confidence intervals: 5.16-10.71 and 4.36-7.75, respectively). The association of IM and PI shows a slight but not significant improvement between 1960 and 1982. AI can be considered a good predictor of IM in countries.