The purpose of this study is to determine the effect of instruction supported by Web 2.0 tools on prospective science teachers' biotechnology literacy. The study was conducted by using experimental pretest-posttest control group design. The sample was composed of 60 prospective science teachers. These prospective science teachers were randomly assigned to experimental and control groups in equal numbers. "Biotechnology Literacy Test" and open-ended questions were used to collect the data. The scientific literacy classification of Bybee (1997) was used as a framework for determining the biotechnology literacy of prospective science teachers. Therefore, biotechnology literacy of the prospective science teachers was examined based on nominal, functional, conceptual, multidimensional literacy levels. According to the results, there was a statistically significant difference between pretest and posttest scores of the experimental group at multidimensional literacy in favor of the posttest. However, there was no significant difference between the control group's pretest and posttest results. When compared groups on the pretest and posttest scores, statistically significant differences were identified at nominal, functional and multi-dimensional literacy levels in post-tests. Moreover, the experimental process influenced the experimental group's decision-making process in their daily life problems. Suggestions were presented under the results obtained from the research.