The results of a sociomedical study performed in a representative group 715 patients of productive age comparising 545 cases of rheumatoid arthritis (RA) and 170 cases of ankylosing spondylitis (AS), are presented in this paper. The set was constituted by means of a stratified selection from 6 districts in Slovakia. Data about the patients were obtained by medical examination accompanied by a sociological survey carried out in the form of a semi-standardized interview. Among the 545 RA patients women prevailed (80.4%), while in the AS group it was men (83.5%). In so far as the age was concerned, most of the RA patients were in their 5th and 6th decades while the AS patients were 10 years younger. 2/3 of the patients with RA had but a primary grade education, a significantly higher level of education could be found among the AS patients. When taking into account the degree of advancement of the disease there was a marked preponderance of medium grade stages among the RA cases (71.3% of the cases were of grades II and III), while among the AS 2/3 of the cases were of grades IV and V. Notwithstanding the more advanced stages of the disease the AS patients were more efficient functionally: 61.2% of them remained in their original employment (while the RA patients only in 45.5% of the cases) and 2.9% of them were entirely dependent upon help of others in self-care (among the RA patients it was in 9.5%). 36.4% of the RA patients and 51.1% of the AS patients whose disease was active were exposed to the effect of the weather in their work. A full invalid rent had to be given to 46.8% of the productive age RA patients and only to 28.8% of those suffering from AS. There was a direct relationship between the patients' labour activity and their eventual relegation to an invalid rent reception state and the degree of their education. In environmental conditions of life the narrow space of the apartment influenced negatively the activity of the rheumatoid process. Understanding and a favourable atmosphere in the family had a positive influence upon the course of the disease and this, not only from the subjective viewpoint but also upon the degree of functional efficiency of the patients, their activity and the dynamics of the inflammatory rheumatoid process (P less than 0.001). A feeling of loneliness was reported by 51.5% of the RA patients even in the productive age and in 35.2% of the AS cases.(ABSTRACT TRUNCATED AT 400 WORDS)