It is not known whether malnourished infants can mount a comprehensive acute-phase protein (APP) response and, if so, whether this is achieved by increasing APP synthesis rates. To address these issues, we measured 1) the plasma concentrations of five APPs (C-reactive protein, α1-acid glycoprotein, α1-antitrypsin, haptoglobin, and fibrinogen) and 2) the synthesis rates of three APPs (α1-antitrypsin, haptoglobin, and fibrinogen) using a constant intragastric infusion of [2H3]leucine in nine infected marasmic children at ∼2 days postadmission ( study 1), ∼9 days postadmission when infections had cleared ( study 2), and ∼59 days postadmission at recovery ( study 3). Except for fibrinogen, the plasma concentrations of all APPs were higher in study 1 than in studies 2 and 3. Although the rate of synthesis of haptoglobin was significantly greater in study 1 than study 2, the rates of fibrinogen and α1-antitrypsin synthesis were similar in all three studies. These results show that 1) severely malnourished children can mount an APP response to infection which does not include fibrinogen and 2) the APP response is accomplished through different mechanisms.