Based on Eccles' expectancy-value model of achievement motivation this study used questionnaires to explore the relationships between students' perceived task demands (perceived task difficulty of A levels and required effort) and their expectations and values attached to A level achievement. Although it has been tested extensively in the US, and more recently in other countries such as Germany (Trautwein et al., 2012) and Australia (Guo et al., 2015; Hood et al., 2012), this model has not previously been investigated in the context of high stakes A level examinations in the UK, and the sample in this study therefore comprised of 930 students from 12 Oxfordshire schools. The students in this study perceived A levels to be difficult and thought they would have to apply effort to their studies to do well in them. Expectations and values were influenced by the required effort associated with A levels, although task difficulty was only related to the overall subjective task value in the year 12 sample. Students who perceived A levels to be difficult were less interested in them, and in the year 12 sample found them less useful. When greater effort was perceived to be required students placed more value on attainment and utility. These findings were largely consistent with Eccles' expectancy-value model. Girls perceived A levels to be harder and require more effort and this is an area for further exploration. [This paper was presented at the British Psychological Society Psychology of Education Section Annual Conference (Edinburgh, Scotland, 2017).]