The study aimed to compare the sugar (1992, 2017) and energy (2017) content of chocolate confectionery available in the UK between 1992 and 2017 using cross-sectional surveys. All major UK retailers operating at the time were included. Sugar content in 1992 was obtained from a booklet and sugar and energy content from 2017 were collected from product packaging in-store. In 1992, the average sugar content of chocolate confectionery was 46.6 ± 10.3 g/100 g and in 2017 it was 47.3 ± 12.1 g/100 g. Sugar content ranged from 0.5 to 75.2 g/100g, with large variations between different categories of chocolate and within the same category of chocolate. There were 23 products found in both 1992 and 2017. The average sugar content per 100 g for these products was 44.6 ± 9.4 g in 1992 and 54.7 ± 6.3 g in 2017, representing a 23% increase in sugar content (p < 0.001). The results show that the sugar content of chocolate confectionery has increased since 1992, which is concerning. However, they also suggest sugar levels can be reduced because (a) lower sugar versions of the same products existed in 1992 and (b) there is a large variation in sugar and energy content between different categories of chocolate and within the same category in 2017.