Background: Dietary polyphenols are bioactive compounds credited with health protection and reducing inflammation. Evidence on their effects is limited in low- and middle-income countries, especially among rural populations. Objectives: To evaluate the association between dietary polyphenols intake and markers of inflammation and endothelial adhesion over 12 mo of follow-up among rural adult women participating in the Cardiopulmonary Outcomes and Household Air Pollution randomized controlled trial. Methods: We used data at baseline and 12-mo visit in 100 healthy women aged 25–64 y living in rural communities in Puno, Peru. We assessed dietary intake using 24-h dietary recalls and measured inflammatory cytokines [interleukin (IL)-10, IL-6, IL-1β, C-reactive protein, tumor necrosis factor-α] and endothelial adhesion (vascular cell adhesion protein-1, intercellular adhesion molecule-1) biomarkers in dried blood spots using immunoassay analyses. We quantified polyphenol intake using the Phenol-Explorer database. We used multivariable linear regression to assess the association between changes (12-mo of follow-up minus baseline) in dietary polyphenols intake, and inflammatory and endothelial adhesion markers at 12-mo. Results: At baseline, mean (±standard deviation) participant age was 49 ± 10 y, mean total polyphenol intake was 335 ± 193 mg/d, and mean phenolic acids intake was 195 ± 80 mg/d. Lower IL-1β concentrations at 12-mo were associated with higher energy-adjusted phenolic acid intake [adjusted mean difference −0.35 pg/mL per mg/d; 95% confidence interval (CI): −0.63, −0.07]. In contrast, higher anti-inflammatory cytokines IL-10 concentrations at 12 mo were associated with higher energy-adjusted intake of stilbenes (0.42 pg/mL per mg/d; 95% CI: 0.18, 0.66) and other polyphenols (0.28 pg/mL per mg/d; 95% CI: 0.10, 0.46). Conclusions: Higher polyphenol intake, particularly phenolic acids and stilbenes, was associated with an improved anti-inflammatory profile in rural women.