Idiopathic lobular panniculitis (ILP) is a chronic disease with multiple organ dysfunction that is regarded as a clinical and pathomorphological variant of lobular panniculitis with typical clinical symptoms. ILP is characterized by alternating periods of stable state (remissions) and active manifestations (exacerbations). The main task in monitoring patients with ILP is assessment of disease activity and identification of prognostically unfavourable factors. However, the “gold standard” has not been developed yet. Objective of the study is to create a scale of assessment of the inflammatory process activity in ILP on the basis of clinical and laboratory parameters. Patients and methods. A total of 67 patients (9 men and 58 women) with a verified diagnosis of ILP were examined. All of them were followed up by Nasonova Research Institute of Rheumatology FGBNU from 2007 to 2017. The patients were aged between 20 and 76 years, the average duration of the disease was 78.91 months. The medical examination included general clinical examination, chest computed tomography, immunological, tuberculosis tests and pathomorphological study of skin biopsy specimens from the node site, determination of the serum concentration of α1-antitrypsin, amylase, lipase, ferritin, creatine phosphokinase, and a body mass index. Results. Analysis of clinical manifestations made it possible to distinguish four forms of ILP: nodal (30 patients), plaque (10), infiltrative (15) and mesenteric (12), which had clinical and laboratory features. We used the obtained data to develop ILP activity index (AI), which described the state of 7 organ systems. The maximum score for individual systems is from 1 to 3 points, depending on the number of parameters being assessed. Conclusions. The proposed ILP IA is of great practical consequence. Further studies and, probably, a search for new ILP activity parameters are necessary.