OBJECTIVES:  A small but growing body of evidence suggests that acute post-prandial hyperglycaemia (PPHG) can have a significant impact on some people with diabetes.  This study was designed to develop a standardised tool to measure the impact of PPHG episodes. METHODS:  Twenty-four adults (≥18 yrs) with Type 1 (n=14) and Type 2 (n=10) insulin-dependent diabetes took part in a qualitative study to describe the experience and impact of PPHG. Data were collected via one-to-one telephone interviews in the US (n=10) and two focus groups in the UK (n=14).  Thematic analysis was conducted on the transcripts to identify emerging themes.  Themes were drawn into measurement domains and described in terms of specific items.  The study protocol was approved by an ethics review board. RESULTS:  The qualitative analysis identified 7 clear domains which could be grouped into two larger groups.  The first 4 domains (25 items) relate to participants’ most recent spike in blood sugar within the last 2 weeks (How I felt; Thinking and Concentration; Work; Awareness).  The remaining 3 domains (22 items) relate more generally to the experience of PPHG after eating (Preventative Behaviours; Worry and Concerns; Management). CONCLUSIONS:  The qualitative research identified a range of different ways that people can be affected by acute PPHG.  This is reflected in the domains of the new measure.  Further validation and testing is required and this is planned in a quantitative study involving 800 participants in the UK and US.  This measure, when finalised, will allow us to better understand the impact and burden of acute PPHG.