This study aimed at investigating the effects of form-focused instruction on students’ writing attitude, motivation and achievement. A pretest-posttest nonequivalent group quasi-experimental research design was used. Two intact classrooms were taken and assigned to the control group (N = 45) and the treatment group (N =45) through simple random sampling technique. Writing achievement tests and Likert scale type questionnaires were used to collect data for the study. The data were analyzed through independent samples t-test. The Pearson correlation (r) and Cohen’s d effect size statistics were also included in the analysis. Results from the first questionnaire on students’ writing attitude indicated that there was statistically significant (t (88) = 6.975, p < 0.05) difference between the study groups along with large effect size (d = 1.47). Results from the second questionnaire about the students' writing motivation were also found to be significant (t (88) = 4.220, p < 0.05) along with a moderate effect size (0.88). Findings from the writing tests were also found to be statistically significant (p < 0.05) in terms of all the identified measuring rubrics. The implication was that the new conditions carried out in the experimental group had played a significant role in improving the students’ writing attitude, motivation and achievement.