Micronutrient-fortified, cereal-based infant foods are recommended for reducing multiple micronutrient deficiencies in low-income countries, but their nutritional quality is not always optimal. In a double-blind randomized trial, we compared the efficacy of a locally produced porridge based on maize, beans, bambaranuts, and groundnuts fortified with 19 (rich) or 9 (basal) micronutrients. Infants aged 6 mo from Lusaka, Zambia were randomized to receive the richly fortified (n = 373) or basal (n = 370) porridge daily for 12 mo along with routine vitamin A supplements. Baseline and final micronutrient status and inflammation (based on α-1-glycoprotein) were assessed using nonfasting blood samples. Baseline prevalence of anemia (39%) and zinc deficiency (51%) were a public health concern. There were overall treatment effects on hemoglobin (Hb) (P = 0.001), serum transferrin receptor (P < 0.001), serum ferritin (P < 0.001), and serum selenium (P = 0.009); biomarker responses for iron and zinc were modified by baseline concentrations, and for Hb and iron by socioeconomic status. At 18 mo, the adjusted odds of anemia, iron deficiency anemia (Hb <105 g/L and transferrin receptor > 11.0 mg/L), and iron deficiency were 0.37 (95% CI = 0.25, 0.55), 0.18 (0.09, 0.35), and 0.30 (0.18, 0.50) times those in the basal group, respectively. The rich level of fortification had no overall treatment effect on serum zinc (1.09; 0.66, 1.80) but improved serum zinc in children with lower Hb concentrations at baseline (P = 0.024). A locally produced cereal- and legume-based infant food richly fortified with micronutrients reduced anemia and improved iron and selenium status but may require reformulation to improve the biochemical zinc status of urban Zambian infants.