This study was conducted to examine the effectiveness of an action plan applied for increasing the level of the strategy, model, method-technique knowledge, and planning and implementation skills of prospective Science teachers. The action research method was used in the study. The participant group consisted of pre-service science teachers attending a state university in 2018. Knowledge test, lesson plan preparation test, and observation form were used as the data collection tools. Descriptive statistics, dependent groups t-test, and content analysis were used to analyze the data. As a result of the research, it was determined that the knowledge level of the teacher candidates after the action was statistically significantly higher than the pre-action knowledge level. It was determined that the pre-service teachers' level of model, strategy, method technique knowledge after the action was statistically significantly higher than their pre-action knowledge level. It was determined that pre-service teachers' planning and implementation skills before and after the action improved compared to the pre-action level. Also, it was observed that the variety of pre-service teachers' method-technique preferences increased after the action compared to before. As a result, it was determined that the action plan was effective in increasing the knowledge level of teacher candidates and in the development of planning and implementation skills. The action plan can be used in teacher training applications by adding new subjects and making improvements.