Suicide mortality was examined between 1970 and 1998 in a cohort of 19,801 persons categorized as indigenous Sami in Arctic Norway. Standardized mortality ratios (SMR) were calculated using the suicide rates of the rural population of Arctic Norway as reference. There was a significant moderate increased risk for suicide among indigenous Sami (SMR = 1.27, 95% Confidence interval (CI): 1.02-1.56). In the study period, 89 suicides occurred in the cohort (70 men and 19 women) with increased suicide mortality both for indigenous Sami males (SMR = 1.27; 95% CI: 0.99-1.61) and females (SMR = 1.27; 95% CI: 0.77-1.99). Significant increased suicide mortality was found for young Sami aged 15-24 for both males (SMR = 1.82; 95% CI: 1.13-2.78) and females (SMR = 3.17; 95% CI: 1.17-6.91). Significant increased suicide mortality was found for indigenous Sami males residing in Sami core area (SMR = 1.54; 95% CI: 1.04-2.20) and for indigenous Sami males not belonging to semi-nomadic reindeer herding (SMR = 1.30; 95% CI: 1.00-1.65). Clusters of suicides in Sami core area may explain the increased suicide mortality found in subgroups among indigenous Sami.