Despite the existence of many studies on the analysis of grammatical errors in writing, little scholarly work reports the errors in academic articles, especially in medical journals. To fill this empirical gap, the present study investigates grammatical errors within written English abstracts of academic articles from a nursing journal in Indonesia. In particular, it attempts to classify the errors based on a surface strategy taxonomy proposed by Dulay, Burt, and Krashen (1982), namely omission, addition, misformation, and misordering. The method used is content analysis. In the omission category, there are several types of errors, including the absence of articles and predicates in the sentences. The next grammatical error is in the category of addition, which includes the addition of “-ing” in the verb of “to infinitive” and “-s” (plural) at one part of a singular parallel sentence. Errors also occur in the misformation category, like subject-verb disagreement, the use of inconsistent tenses, the absence of “-s” in the plural form, and the absence of “-s” in the predicate (verb) that used the third singular person as a subject. However, misordering categories are not found in the data analysis. Overall, the most commonly found errors were in the category of misformation.  The findings of this research are expected to serve as a reference for future scholars when avoiding  errors in writing English abstracts for academic articles.