A study was conducted in new patients registered with tuberculosis (TB) in a rural district of Malawi to determine (i) the prevalence of malnutrition on admission and (ii) the association between malnutrition and early mortality (defined as death within the first 4 weeks of treatment). There were 1181 patients with TB (576 men and 605 women), whose overall rate of infection with human immunodeficiency virus (HIV) was 80%. 673 TB patients (57%) were malnourished on admission (body mass index [BMI] < 18.5 kg/m2). There were 259 patients (22%) with mild malnutrition (BMI 17.0-18.4 kg/m2), 168 (14%) with moderate malnutrition (BMI 16.0-16.9 kg/m2) and 246 (21%) with severe malnutrition (BMI < 15.9 kg/m2). 95 patients (8%) died during the first 4 weeks. Significant risk factors for early mortality included increasing degrees of malnutrition, age > 35 years, and HIV seropositivity. Among all the 1181 patients, 10.9% of the 414 patients with moderate to severe malnutrition died in the first 4 weeks compared with 6.5% of the 767 patients with normal to mild malnutrition (odds ratio 1.8, 95% confidence interval 1.1-2.7). In patients with TB, BMI < 17.0 kg/m2 is associated with an increased risk of early death.