This study was carried out with the purpose of assessing students’ paragraph writing problems and its causes at Injibara secondary school focusing on grade 11 students. This study employed descriptive survey research design. In grade 11, there are 500 students with ten sections. Among the total population of the research, 50 students and four grade 11 EFL teachers were selected as a sample group by using simple random and comprehensive sampling techniques. The data were collected through test, questionnaire and observation. Then, the data gathered through these tools were organized and analyzed using both qualitative and quantitative methods. The data obtained from test and close ended questionnaire were analyzed quantitatively by using frequency and percentage as well as the data obtained by observation and open ended questions were analyzed qualitatively by using word interpretation. The result of the study revealed that students had several problems when they were writing paragraphs in English. These problems include lack of paragraph development, lack of unity in the paragraph, redundancy or repetition of words, sentence fragment, spelling problem, capitalization, punctuation, verb tense, subject verb agreement, word order, word choice, transition words or conjunction, pronouns and articles. Among the problems that were faced by students, lack of paragraph development, lack of unity in the paragraph, sentence fragments, spelling problems, capitalization, punctuation and wrong use of conjunctions were the most dominant problems of students had in paragraph writing due to lack of learners’ motivation, lack of students’ knowledge how to write and develop paragraph using the four paragraph development patterns, shortage of vocabulary adequacy, lack of time to write paragraph in the classroom, teachers give less emphasis for paragraph writing lesson, EFL teachers’ assessment method and unable to give constructive feedback. It is recommended that teachers should give proper and adequate attention to paragraph writing techniques, practice, how to develop paragraph using the four main types of paragraph development patterns and giving feedback on students writing paragraph.