Aim of the work: To assess the role of urinary and tissue monocyte chemoattractant protein-1 (MCP-1) in active lupus nephritis (LN) and to correlate the levels with disease activity and renal status. Patients and methods: Urinary and tissue MCP-1 were determined in 42 systemic lupus erythematosus (SLE) patients with LN. 20 matched controls were considered. SLE disease activity index (SLEDAI) was recorded in all patients. Urinary and renal tissue MCP-1 was evaluated. Renal biopsy was performed in active LN patients for histopathological classification and correlation. Results: 22 active LN patients (22.8 ± 4.7 years old) and 20 inactive (24.6 ± 4.3 years old) were studied. They were 39 female and 3 males (F:M 13:1). The urinary MCP-1 was significantly higher in active LN patients (1072.8 ± 658.4 pg/mg creatinine) compared to the inactive group (151.3 ± 103.5 pg/mg creatinine) and both were significantly higher than the level in the controls (19 ± 17.8 pg/mg creatinine) (p < 0.001). A significant correlation was present in the active LN patients between urinary MCP-1 level and proteinuria, anti-dsDNA, renal SLEDAI and biopsy activity index and negatively with C3 and C4. There was a significant correlation of the glomerular MCP-1 renal tissue expression score with the renal SLEDAI, anti-dsDNA, biopsy activity index and urinary MCP-1 and negatively with C3. Tubulointerstitial MCP-1 score significantly correlated with urinary MCP-1. Urinary, glomerular and tubular MCP-1 showed a sensitivity of 97%, 64% and 4% and specificity of 100%, 95% and 20% respectively in detecting LN. Conclusion: MCP-1 could be a valuable marker for LN and disease activity.