Background: Psoriasis is a chronic proliferative inflammatory cutaneous condition manifested by pathological cutaneous lesions caused by multiple external and internal causes. This research aims to evaluate the IMA serum levels in psoriasis vulgaris cases and compare with healthy controls. Methods: This case control research was performed on sixty male and female psoriasis vulgaris patients with age ≥ 18 years and tewnty age and sex matched healthy control. All patients underwent general examination, clinical examination of the psoriatic lesions and laboratory investigation for measurement of IMA serum level. PASI score was utilized for disease severity evaluation. Results: Age, gender, disease duration and PASI score were insignificantly different between the study groups. BMI was significantly different between the study groups (P < 0.001). BMI showed a significant difference between paired groups, group I & IV and group II & III (P < 0.001, P < 0.001; respectively). BMI was significantly lower in group I than group II (P < 0.001) and was significantly lower in group III than group IV (P < 0.001). Conclusions: Obesity is a common comorbidity with psoriasis which may worsen the disease progression by adding more ROS to the pathogenesis of psoriasis. Obese psoriatic patients were shown to have a greater IMA than non-obese psoriatic patients.