This study describes the self-reported health and well-being status of field and packhouse workers in UK vegetable horticulture, and tests the null hypothesis that there is no difference in the self-reported health of workers on organic and conventional horticultural farms. The majority of those sampled were migrant workers (93%) from Bulgaria, Latvia, Lithuania, Poland, Russia and the Ukraine. More than 95% of the respondents were aged 18-34 and recruited through university agricultural faculties in East European or employed via UK agencies. The health of 605 farm workers (395 males and 210 females) was measured through the use of four standard health instruments. Farm workers' health was significantly poorer than published national norms for three different health instruments (Short Form 36, EuroQol EQ-5D and the Visual Analogue Scale). There were no significant differences in the health status of farm workers between conventional and organic farms for any of these three instruments. However, organic farm workers scored higher on a fourth health instrument the Short Depression Happiness Scale (SDHS) indicating that workers on organic farms were happier than their counterparts working on conventional farms. Multiple regression analysis suggested that the difference in the SDHS score for organic and conventional farms is closely related to the range and number of tasks the workers performed each day. These findings suggest that a great deal of improvement in the self-reported health of farmers will need to occur before organic farms meet the requirements of the 'Principle of Health' as described by IFOAM. Ensuring that farm workers have a varied range of tasks could be a cost effective means of improving self-reported health status in both organic and conventional farming systems.