Objectives: The study aimed to compare the scores of the comprehensive ICF core set for Multiple Sclerosis (cICF-MS) in patients with Multiple Sclerosis (PwMS) who were diagnosed the same or next year from onset and who were diagnosed later, and if there were differences found, to analyse their value for prediction of current work capacity. Methods: 151 PwMS took part in the cross-sectional study. The average time from diagnosis of MS in the whole sample was 11 years. The neurologist assessed PwMS by telephone interview using the cICF-MS. Additionally, clinicodemographic data (age, gender, education, employment, disease type, disease-modifying treatments, comorbidities, EDSS, date from onset and date of diagnosis) and the data about their working capacity were collected. Results: 96 PwMS were diagnosed the same or the next year from diagnosis, and 55 within two or more years from onset. These groups do not differ by all clinicodemographic data. Nevertheless, there were found 13 differences in cICF-MS between groups (b152 Emotional functions, b156 Perceptual functions, b310 Voice functions, b320 Articulation functions, b330 Fluency and rhythm of speech functions, b5105 Swallowing, b735 Muscle tone functions, b7650 Involuntary contractions of muscles, d415 Maintaining a body position, d420 Transferring oneself, d430 Lifting and carrying objects, d530 Toileting, d930 Religion and spirituality) with more considerable impairment in delayed diagnosis group. Only three categories (Maintaining a body position, Perceptual functions and Muscle tone functions) were predictors of PwMS work capacity, with R2=.377. Conclusions: The study revealed that delayed diagnosis of MS may result in some functional impairment at follow-up, which in turn is related to reduced work capacity.