This study investigated writing errors committed by engineering students at AnNajah National University in Palestine and compared these errors based on school type. It analyzed errors in essays of 54 undergraduate students, 28 attended governmental schools, and 26 attended private schools. Errors were classified based on James's taxonomy. Results showed that both groups faced the same problems when writing in English, as the frequency of committed errors for both groups had the order of morphology, spelling, punctuation, formal, syntactic, semantic and ordering, except for formal errors being higher than punctuation for private school students. The study also concluded that no statistical significant differences were apparent in frequency of errors committed by the two groups. This indicates that private school students do not outperform their governmental school peers in school performance. Such results are necessary for parents and for the Ministry of Education as they oppose the general belief that performance of private school students is better.