Errors made by students in skills such as speaking and writing have been treated as important information to help teachers direct the foci of their teaching. Teachers need to pay attention to the most serious errors before addressing other errors. Hence, this research was aimed at finding the most serious errors produced by students at one of the junior high schools in Indonesia, i.e. State Junior High School No 7 in Banda Aceh. The errors were categorized into surface strategy taxonomy and linguistic category taxonomy errors. The data were collected from recount texts produced by 19 students who were known to make errors in writing. The data was analyzed by calculating the percentage of errors based on the total cumulative errors for surface strategy taxonomy, but based on the number of attempts in the same grammatical elements for linguistic category taxonomy. The results of data analysis showed that the dominant errors for surface strategy taxonomy were selection (72%) followed by omission (14.4%), and addition (10.6%). In the linguistic category taxonomy, the most dominant types were word forms (48.4%), followed by articles (35%), nonfinite verbs (34.9%), verb tenses (34.3%), plurals (33.3%), and prepositions (30%). It is suggested that teachers pay more serious attention to the most serious problems because solving these problems will hasten the students' progress in learning.