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Background and Importance Therapeutic drug monitoring (TDM) is increasingly used to optimise anti-TNF therapy in inflammatory bowel disease (IBD). Nutritional status and systemic inflammation may influence drug clearance, but comparative real-world evidence between different anti-TNF is scarce.Aim and Objectives To evaluate the association between analytical parameters and trough concentrations of adalimumab and infliximab in routine clinical practice.Material and Methods Retrospective observational study conducted over seven months in patients treated with adalimumab or infliximab for IBD. Analytical variables included serum albumin, C-reactive protein (CRP), faecal calprotectin, leukocytes, neutrophils, and erythrocyte sedimentation rate. Correlations between analytical parameters and trough concentrations were assessed, and multivariable linear regression was applied to explore independent associations.Results 185 patients were analysed. Adalimumab cohort: 40 patients (42 determinations), mean age 44 ± 16 years (range 13–74), mean bodyweight 68 ± 12 kg; median trough 12.1 µg/mL. Albumin correlated positively with trough concentrations (r = 0.41, p = 0.03) and remained significant after adjustment. CRP (r = –0.15, p = 0.45) and faecal calprotectin (r = –0.10, p = 0.62) were not significant. Infliximab cohort: 145 patients (420 determinations), mean age 47 ± 20 years (range 4–85); median trough 8.0 µg/mL. Negative correlations were observed with CRP (ρ = –0.24, p < 0.01), leukocytes (ρ = –0.31, p = 0.005) and neutrophils (ρ = –0.40, p < 0.001), while albumin showed a non-significant positive trend (ρ = 0.11, p = 0.08). After multivariable adjustment for the aforementioned covariates, CRP, leukocytes, and neutrophils remained independently associated with lower infliximab levels.Conclusion and Relevance In this real-world IBD cohort, serum albumin was positively associated with adalimumab concentrations, whereas infliximab levels correlated inversely with systemic inflammatory markers (CRP, leukocytes, neutrophils). These findings support the value of routine analytical parameters in the interpretation of anti-TNF drug monitoring and highlight the need for prospective studies to confirm these associations and guide individualised treatment strategies.Conflict of Interest No conflict of interest