The main objective of this study was to investigate theories and practices of writing. To achieve this objective, qualitative data were collected using qualitative content (document) analysis, observation, and interview. The participants of the study were selected from North Shoa Zone Preparatory Schools. Five sections for observation and ten students for interview were selected purposefully. The document data were analyzed using qualitative content analysis technique. The observation and the interview data were analyzed using thematic analysis method. The document analysis revealed that the process and the genre-based approaches were predominantly reflected in the writing tasks of the Grade 11 English language teaching materials. The process-approach, informed by the cognitive learning theory, and the genre-based approach, based on the functional and the socio-cultural theories are meaning oriented. However, the observation and the interview data analysis results demonstrated that the product approach was mainly used in the writing classes. Informed by the behaviorist and the structural theories, the product approach is form-oriented. Thus, inconsistencies were observed between the theories involved in the teaching materials and the methods used in the practices of writing; the theories could promote learners' communicative competence of writing though the practice still continued using the form-oriented approaches.