PURPOSE: Lower urinary tract symptoms (LUTS) are very common among older men globally, but evidence regarding the relationship between LUTS and country of origin is limited. This study aimed to investigate the relationship between the prevalence of LUTS and region of birth in a large, ethnically diverse population of older men resident in New South Wales, Australia. METHODS: Data on LUTS, demographic and behavioural factors were collected by postal questionnaire from 2006 to 2009 and analysed for 95,393 men aged 45 and over from the 45 and Up Study, who had not had previous prostate surgery. Logistic regression was used to investigate the association between region of birth and moderate/severe LUTS, ascertained using a modified International Prostate Symptom Score, adjusting for age, income, education, alcohol consumption and smoking. RESULTS: Overall, 18,530 (19.4 %) men had moderate or severe LUTS. Compared to Australian-born men, prevalence of moderate/severe LUTS was significantly higher in men born in the Middle East & North Africa, Southeast Asia and North America regions (adjusted odds ratios (OR) = 1.43; 95 % CI = 1.23-1.66, OR = 1.25; 1.10-1.42, OR = 1.26; 1.05-1.52, respectively), whereas men from the UK & Ireland had significantly lower prevalence (OR = 0.85; 0.80-0.90). Patterns of association were generally similar for storage- and voiding-related types of LUTS. However, participants born in Sub-Saharan Africa showed a significantly elevated prevalence of moderate/severe voiding symptoms (1.22; 1.03-1.45) but not storage symptoms, compared to Australian-born respondents. CONCLUSION: The prevalence of LUTS and of specific subtypes of LUTS varies according to region of birth.