Current methods of clinical assessment in osteoarthritis show a high degree of variability. By contrast, patients with rheumatoid arthritis may be evaluated using a number of standardised and validated indices. One hundred patients with primary osteoarthritis of the hip and knee were interviewed in order to determine the dimensionality of their discomfort and disability and to define the clinical importance of each component item. The symptomatology of osteoarthritis was captured by five pain, one stiffness, twenty-two physical, eight social and eleven emotional items. In spite of a high degree of variability in the frequency of involvement of the individual items, their clinical importance was similar both within as well as across dimensions. Further studies are indicated to determine the reliability, validity and responsiveness of each of the items identified as a prelude to developing a standardized method of assessing patients with osteoarthritis of the hip and knee.