Household food insecurity (HHFI) may be a barrier to both optimal maternal nutritional status and infant feeding practices, but few studies have tested this relationship quantitatively, and never among HIV-infected individuals. We therefore described the prevalence of HHFI and explored if it was associated with poorer maternal nutritional status, shorter duration of exclusive breastfeeding (EBF) and fewer animal-source complementary foods. We assessed these outcomes using bivariate and multivariate analyses among 178 HIV-infected pregnant and breastfeeding (BF) women receiving combination antiretroviral therapy in the PROMOTE trial (NCT00993031), a prospective, longitudinal cohort study in Tororo, Uganda. HHFI was common; the prevalence of severe, moderate, and little to no household hunger was 7.3, 39.9, and 52.8 %, respectively. Poor maternal nutritional status was common and women in households experiencing moderate to severe household hunger (MSHH) had statistically significantly lower body mass index (BMIs) at enrollment (21.3 vs. 22.5, p < 0.01) and prior to delivery (22.6 vs. 23.8, p < 0.01). BMI across time during pregnancy, but not gestational weight gain, was significantly lower for MSHH [adjusted beta (95 % CI) −0.79 (−1.56, −0.02), p = 0.04; −2.06 (−4.31, 0.19), p = 0.07], respectively. The prevalence (95 % CI) of EBF at 6 months was 67.2 % (59.7–73.5 %), and the proportion of women BF at 12 months was 80.4 % (73.3–85.7 %). MSHH was not associated with prevalence of EBF at 6 months or BF at 12 months. However, among those women still EBF at 4 months (81.4 % of population), those experiencing MSHH were significantly more likely to cease EBF between 4 and 6 months (aHR 2.38, 95 % CI 1.02–5.58). The prevalence of HHFI, maternal malnutrition, and suboptimal infant feeding practices are high and the causal relationships among these phenomena must be further explored.