The aim of this study was to explore if self-rated pain intensity and severe pain differed significantly between immigrants from different regions, and if other socio-economic, or clinical, characteristics could predict severe pain. A total of 129 men and 217 women at a primary health centre in Stockholm, Sweden, 27-45 years, on long-term sick leave, were recruited in consecutive order and grouped into a Turkish (n = 122), Southern European (n = 52), Middle East (n = 69) and one Mixed (n = 173) group of immigrants. All were employed in service jobs. Somatic status, depression and level of psychosocial stressors, including pain anxiety, were established by standardized procedures. All reported long-standing disabling back pain. Patients rated intensity of pain ''right now'' on a 0-100 mm visual analogue scale (VAS) as a last part of the consultation with two doctors. Severe pain was defined as VAS 75-100. Median values (md) with inter-quartile ranges (IQR) were calculated for interval and ordinal data. Non-parametric statistics were used to calculate significant differences between groups. Crude and age-standardized odds ratios (OR) with 95% confidence intervals (95% CI) as rating severe pain were calculated by binary and forward conditional logistic regression. Men and women were analyzed separately. Women had more tender points, (P \ 0.001), and reported pain anxiety more often (P \ 0.01). Frequency of depression did not differ between the immigrant groups. The VAS-values varied, but not significantly, between the immigrant groups of men and women. Men had lower VAS values than women (md 50, IQR 36-69 vs. md 72, IQR 51-85), (P \ 0.001). Women had a three-fold risk to rate severe pain (OR 2.9, 95% CI 1.8-4.7). By sex, no immigrant group had significantly elevated OR to rate severe pain. Being 40-45 year old doubled the OR as rating severe pain. Men with depression, or little education, had high risks as rating severe pain (age-standardized ORs 4.1; 95% CI 1.7-10.0 and 2.7; 95% CI 1.1-6.8, respectively), and so had depressed women (age-standardized OR 1.9; 95% CI 1.1-3.4). Women with pain anxiety had a doubled, not statistically significant, elevated risk (age-standardized OR 2.0, 95% CI 0.95-4.3). The groups did not differ significantly in pain intensity or severe pain. Severe pain was predicted by depressed mood and probably linked to gender, age and sick roles.