This paper addresses to evaluate and assess the students' competency in writing skills at Secondary school level in the English Language focusing five major content areas: word completion, sentence making/syntax, comprehension, tenses/grammar and handwriting. The target population was the male and female students of grade 10 of urban and rural Secondary schools from public and private sector. Forty (40) Secondary schools of District Bahawalnagar, Pakistan were taken using stratified sampling. A sample consisting of 440 students (11 students from each school) was randomly selected using a table of random numbers. An achievement test consisting of different items was developed to assess the students' competency and capability in sub-skills of writing such as word completion, sentence making/syntax, comprehension, tenses/grammar and handwriting. Mean score and standard deviation were used to analyze the students' proficiency in each sub-skill. The t-test was applied to make the comparison on the bases of gender, density and public and private sector. The overall performance of all the students was better in comprehension as compared to other sub-skills namely word completion, sentence making/syntax, tenses/grammar and handwriting. The analysis, based on t-value, revealed no significant difference between the performance of male and female students and the students of public and private schools, whereas there was a significant difference between the performance of urban and rural students.