BackgroundOutcomes of diabetes care are unequal and the NHS has a duty to consider reducing inequality in healthcare outcomes.AimTo quantify trends in socioeconomic inequality and diabetes outcomes.Design and settingWhole-population longitudinal study of 32 482 neighbourhoods (Lower Layer Super Output Areas [LSOAs]) in England between 2004/2005 and 2011/2012.MethodSlope indices of inequality (SIIs) between neighbourhoods of great and little deprivation were measured annually for: glycated haemoglobin control in people with diabetes; emergency hospitalisation for diabetes; and amenable mortality from diabetes.ResultsFrom 2004/2005 to 2011/2012 glycaemic control improved in all social groups, regardless of deprivation level, although inequality was unchanged as measured by the SII (0.04, 95% confidence interval [CI] = -0.43 to 0.52). Diabetes-related amenable mortality improved in all social groups, but decreased at a faster rate in neighbourhoods of greater deprivation. Inequality in diabetes-related amenable mortality improved, with the SII falling by 2.68 (95% CI = 1.93 to 3.43), resulting in 594 (95% CI = 420 to 767) fewer deaths. In contrast, emergency hospitalisations for diabetes increased in all social groups, with faster growth in neighbourhoods of greater deprivation. The socioeconomic gradient increased with the SII widening by 19.59 admissions for diabetes per 100 000 (95% CI = 16.00 to 23.17), resulting in an increase of 5991 (95% CI = 5084 to 6899) excess admissions associated with socioeconomic inequality during the study period.ConclusionIn diabetes, mortality declined faster, but emergency hospitalisation grew faster in more deprived neighbourhoods. Unequal growth in emergency hospitalisation for diabetes is likely to be partly due to increased diabetes prevalence and patients living longer, but may also be due to overuse of glycaemic control medication.