The Dietary Approaches to Stop Hypertension (DASH) diet is an effective measure in the prevention and treatment of CVD. We evaluated recent trends in socio-economic differences in the DASH score in the UK population, using education, occupation and income as proxies of socio-economic position (SEP). We analysed data on 6416 subjects aged 18 years and older collected in the National Diet and Nutrition Survey (2008–2016). The DASH score was calculated using sex-specific quintiles of DASH items. Multiple linear regression and quantile regression models were used to evaluate the trend in DASH score according to SEP. The mean DASH score was 24 (sd 5). The estimated mean difference between people with no qualification and those having the highest level of education was −3·61 (95 % CI −4·00, −3·22) points. The mean difference between subjects engaged in routine occupations and those engaged in high managerial and professional occupations was −3·41 (95 % CI −3·89, −2·93) points and for those in the first fifth and last fifth of the household income distribution was −2·71 (95 % CI −3·15, −2·28) points. DASH score improved over time, and no significant differences in the trend were observed across SEP. The widest socio-economic differences emerged for consumption of fruit, vegetables, whole grains, nuts, seeds and legumes. Despite an overall increase in the DASH score, a persisting SEP gap was observed. This is an important limiting factor in reducing the high socio-economic inequality in CVD observed in the UK.