Five years have elapsed since the International Conference on Malnutrition, Learning, and Behavior at the Massachusetts Institute of Technology. The present Seminar was held to examine progress since then. The following papers were presented and discussed: "Malnutrition and the Nervous System," Donald B. Cheek, A. B. Holt, and E. D. Mellits; "Lasting Deficits and Distortions of the Adult Brain Following Infantile Undernutrition," John Dobbing; "Some Speculations on Mechanisms Involved in the Effects of Undernutrition on Cellular Growth," Myron Winick, J. A. Brasel, and Pedro Rosso; "Small-for-Dates Offspring: An Animal Model," R. J. C. Stewart; "Empirical Findings with Methodologic Implications in the Study of Malnutrition and Mental Development," Robert E. Klein et al.;"Malnutrition and Mental Capacity," Fernando Monckeberg; "The Influence of Malnutrition on Psychologic and Neurologic Development: Preliminary Communication," Jan Hoorweg and Paget Stanfield; "The Functioning of Jamaican School Children Severely Malnourished During the First Two Years of Life," Herbert G. Birch and Stephen A. Richardson; "Environmental Correlates of Severe Clinical Malnutrition and Language Development in Survivors from Kawshiorkor or Marasmus," Joaquin Cravioto and Elsa DiLicardie; "Ecology of Malnutrition: Nonnutritional Factors Influencing Intellectual and Behavioral Development," Stephen A. Richardson; "Issues of Design and Method in Studying the Effects of Malnutrition on Mental Development," Herbert G. Birch; and, "Nutrition, Public Health, and Education," Jack Tizard. (JM)