The study assessed error-correction techniques used in correcting students' essays in English language and also determined the effects of these strategies and other related variables on students' performance in essay writing with a view to improving students' writing skill in English language in South Western Nigeria. A quasi-experimental design was adopted for the study. The sample comprised of 180 SSII students who were randomly selected. The students were assigned to experimental groups: Indirect techniques (68), direct metalinguistic (63) and the control group (65). The results showed that the indirect approach was the most effective (x=11.88) compared to the direct metalinguistic technique (x=11.53) and the conventional method (x=10.4), F (2,177)=7.12, p less than 0.05. In conclusion, the implications of the findings are discussed.