Aims: We aimed to evaluate the frequency of consanguinity among the parents of patients with rheumatoid arthritis (RA) and the influence of parental consanguinity on several clinical and laboratory parameters which reflect the severity of the disease. Methods and patients: The study population consisted of 265 patients with RA which were divided into two groups with respect to the presence or absence of consanguinity between their parents. The frequency of parental consanguinity was compared with the general population. The two groups were compared with respect to family history of RA, the age of onset, the age at which RA was diagnosed, duration of the disease, the presence of rheumatoid nodules, vasculitis, serositis and the need for orthopaedic surgery, amyloidosis, the presence and level of rheumatoid factor and anti-cyclic citrullinated peptide antibodies, erosive changes on radiographs, and the need for anti-tumour necrosis factor therapy. Results: Twenty-one patients (8%) had parents who were consanguineous, which was not more frequent compared with the general population (14%). The mean age of disease onset and the mean age at which RA was diagnosed were lower in patients with parental consanguinity, although the difference was not statistically significant. The other clinical and laboratory parameters were also not different between the two groups. Conclusion: The present data suggests that parental consanguinity has no effect on disease severity, and the frequency of consanguinity is not increased among the parents of patients with RA. A possible exception is the earlier disease onset and age at diagnosis which needs to be confirmed by larger studies.