Danish early-phase adolescents only consume one-third of the officially recommended amount of fish. The objective of this study is to investigate the effect of a five week sensory-based experiential theme course with fish on 11- to 13-year old early-phased adolescents' food literacy and acceptance of fish. Study design was a quasi-experimental intervention. 32 Food Knowledge school classes were recruited from the eastern part of Denmark. Classes were assigned to intervention group (n = 185), control group 1 (n = 123), only baseline and follow-up survey, or control group 2 (n = 75): one oral lecture between baseline and follow-up survey. Mixed methods strategy was applied: baseline and follow-up survey, participant observation, telephone-, and group interviews. Before between study group analysis control groups were pooled. The following key effects of the intervention were observed: knowledge on fish and cooking increased within specific areas, skills related to fish and cooking increased, especially in girls. Furthermore, the social dimension and helping each other were important elements. In the intervention group no positive effects were observed for liking or assessment of fish disgust; however, theme course evaluation showed that 47% had become curious on tasting other kinds of fish and 38% stated a higher liking for fish after participation. Furthermore, teachers reported an increase in acceptance of fish in the children as a result of participating. In conclusion food literacy and fish acceptance were increased through participation in a five week sensory-based experiential theme course with fish.