Aim This study was designed to assess the serum levels boron (B), copper (Cu), and zinc (Zn) in patients with juvenile idiopathic arthritis (JIA), and to evaluate their relationships with the disease activity parameters. Patients and methods This study was conducted on 30 children with JIA and 20 apparently healthy children. Patients were subjected to a thorough history‑taking, clinical examination, plain radiography of both hands, and laboratory investigations including erythrocyte sedimentation rate, C‑reactive protein, rheumatoid factor, and antinuclear antibodies. Disease activity was measured using the Juvenile arthritis disease activity score 27 (JADAS‑27 score). Serum B, Cu, and Zn levels were also measured. Results The mean serum B level was highly statistically significantly lower in the JIA patients’ group than that in the control group. The mean serum Cu level was highly statistically significantly higher in the JIA patients’ group than that in the control group. Finally, the mean serum Zn level was statistically insignificantly lower in the JIA patients group than that in the control group. There were significant negative correlations between serum B concentrations and tender joint count (TJC). There were significant positive correlations between serum Cu concentrations and TJC, erythrocyte sedimentation rate, and JADAS‑27. There were significant negative correlations between serum Zn concentrations and TJC and JADAS‑27. Conclusion B serum level may play a role in the pathophysiology of JIA and its severity. Serum levels of B, Cu, and Zn seem to be of fundamental importance in the assessment of a JIA patient.