This study examines the effect of 8th graders’ reading motivation on their writing motivation through structural equation modeling and concentrates on the variables of gender and the like to read and write. The study is supported by relational screening model, and includes a study group formed through simple random sampling (310 8th-grade students). Reading Motivation and the Writing Motivation scales were used for data collection. The study benefited from SPSS 23 and AMOS 22.0 for data analysis through structural equation modelling. Maximum Likelihood method was utilized for estimating the parameters related to the models which were created for analyzing the role of gender and the interest to read and write in the effect of participants’ reading motivation on their writing motivation. The compliance indexes of χ2/df, CFI, GFI, TLI, NFI, IFI, RMSEA ve SRMR were also used. It has been found that all hypotheses models are valid; that reading motivation explains writing motivation by 35% and it has a direct impact on writing motivation. Reading motivation in the female-student model explains writing motivation by 41% whereas this impact is insignificant in the male-student model. In the model regarding students interested in reading and writing, reading motivation explains writing motivation by 39% and 35% respectively, and it has a great impact on writing motivation. Nevertheless, this impact is insignificant in the models regarding participants who are not interested in reading and writing. Departing from these results, it can be stated that reading motivation is a significant predictor for writing motivation and that the affective state of students determines their interest in reading and writing.