This study analyzed the errors in writing frequently committed by the math, science, and engineering regular faculty of the Liceo de Cagayan University. The analysis of the essays was done by identifying the errors and categorizing them according to the grammar items and writing mechanics. The distribution of frequency and percentage were used to determine the order of errors. The tabulation included the actual number of usage and the number of correct and erroneous usage. As found out, the essays contained errors in grammar and punctuation, though relatively low. As ranked, the first five frequent errors were in the use of tenses, preposition, noun inflection, article, subject-verb agreement, and punctuation. Errors in conjunction, verb form, pronoun, and modifier (descriptive) were less frequent. The findings make language retooling program and other academic-related activities necessary in order for the faculty to achieve accuracy in the use of English.