Background: Cutaneous viral warts are benign epidermal proliferations caused by human papillomaviruses (HPVs). Despite treatment, a significant proportion of warts fail to resolve, becoming recalcitrant. Vitamin A (retinol) may disrupt the interplay of HPV replication and epithelial cell differentiation, allowing normal tissue to replace warts. Circulating retinol‐binding protein (RBP) concentrations highly correlate with retinol levels. Aim: We aimed at evaluation of serum RBP level in patients with recalcitrant cutaneous warts in order to assess its correlation with disease pathogenesis. Methods: Serum RBP level was measured by an ELISA technique in 50 patients with recalcitrant cutaneous warts and 30 apparently healthy controls. Results: Serum RBP level was significantly lower in patients with recalcitrant warts than the control group (P < 0.001). However, it did not differ regarding different clinical parameters in studied patients (P > 0.05 each). RBP is a reliable biomarker for significant early detection and discrimination between patients and healthy controls (P < 0.001) at a cutoff value ≤1034.6 μg/ml, with sensitivity and specificity (100% each). Conclusion: Our results revealed that low serum RBP as a relatively cheap biomarker with high specificity and sensitivity is a reliable indicator of vitamin A (retinol) deficiency that may play a role in the pathogenesis of recalcitrant cutaneous warts among our studied patients.