Background: Despite the compelling scientific evidence on the superiority of stroke unit care, far from all acute stroke patients have access to stroke unit care. In congruence with what has been observed when other new methods are introduced in health care, we hypothesized that there has been an inequality in the buildup phase of stroke units but that the gradients between patient groups have decreased as the total capacity of stroke unit care has increased. The purpose of this study was to explore if patients in a national sample who were socioeconomically disadvantaged (low education or low income) had reduced access to stroke unit care and if differences varied over time. Methods: All patients 18-74 years of age registered between 1995 and 2009 in Riks-Stroke, the Swedish stroke register, were included. The Stroke Unit Trialists' definition of a stroke unit has been adopted by Riks-Stroke and hospitals participating in the registry. Basic patient characteristics, stroke risk factors, process and outcome variables are recorded in Riks-Stroke. Socioeconomic data were accessed from Statistics Sweden. Multiple logistic regression analyses were used to calculate odds ratios (ORs) for stroke unit care between prespecified patient subgroups. Results: A total of 319,240 stroke patients were included in Riks-Stroke during the years 1995-2009, and 124,173 were aged between 18 and 74 years; they were included in the final analyses. After adjustment for confounders in a multiple regression model, women were treated in stroke units slightly less often [OR 0.97, 95% confidence interval (CI) 0.95-0.99]. There were no statistically significant associations between stroke unit care and age or between stroke unit care and cohabiting or living alone. The highest level of education predicted access to stroke unit care (secondary vs. primary school: OR 1.04, 95% CI 1.01-1.07; university vs. primary school: OR 1.06, 95% CI 1.02-1.10). Differences according to level of education diminished over time (p = 0.001). Income was not independently associated with stroke unit care, and over time the proportion of patients treated in stroke units increased at a similar rate in all income groups (p = 0.12). Conclusions: Even in a country with modest socioeconomic differences in the general population and public financing of all acute hospital care, socioeconomic inequalities in access to stroke unit care were evident during the early years, but they diminished as the total capacity for stroke unit care increased.