The child poverty rate has increased noticeably in Finland since the mid-1990s, and there are numerous studies in this area. However, little is known about child poverty in the two native and equal population groups, Finnish speakers and Swedish speakers. Using detailed register-based data that cover the period 1987-2011, we analyze how child poverty depends on parental ethno-linguistic affiliation, and whether there is variation in income poverty across these households over time. The poverty measure is relative and based on equalized taxable household income of households with children. Odds of poverty are estimated with logistic regression models using generalized estimating equations to account for repeated observations at the household level. The analyses are restricted to areas with both Swedish-and Finnish-speaking settlement. Single-parent and two-parent households are analyzed separately. Poverty rates increased in all major types of households during the study period, but variation by ethno-linguistic affiliation was fairly modest. Swedish-speaking single-parent and two-parent households experienced a smaller increase in the poverty rate than Finnish-speaking ones, while patterns observed for exogamous households were less clear. The contribution of control variables on the ethno-linguistic poverty differences was modest. Considering that the ethno-linguistic groups studied are indigenous and equal, the small differences in poverty rates between Finnish speakers and Swedish speakers are evidence of a democratic and well-functioning welfare state, although the increasing overall poverty rates over time require future scrutiny by both policy makers and researchers.