How to make learning more interesting is a basic challenge for school education. In this Finnish study, the international ROSE questionnaire was used to survey, during spring of 2003, the relationship between interest in biology and out-of-school experiences for 3626 ninth-grade pupils. Interest and experience factors were extracted by using the explorative factor analysis. Out-of-school, nature-related experiences, including watching nature programs on television, reading on nature from books or magazines, or having out-of-doors, nature-related hobbies were the most important factors correlating with interest in various contexts of human biology/health education like health and illness, personal appearance and fitness, human body in extreme conditions and in general biology like zoology, applied biology and genetics, and evolution. Out-of-school experiences in science and technology-related activities, such as using science kits and constructing models, had surprisingly the highest correlation with an interest in basic processes in biology, such as conceptually more abstract phenomena in ecology or cell biology. Design and technology-related experiences, such as using large tools, or experiences in using computers and mobile phones, were the least important factors to correlate with the studied interest contexts. More boys than girls were interested in basic processes of biology, while more girls than boys found human context interesting. When planning biology lessons and field work, it is important to connect pupils' out-of-school, nature-related hobbies and experiences to biology education, because they may represent longer-lasting personal interests. (Most of this paper is a summary of Uitto, Juuti, Lavonen, & Meisalo, 2006.)