The current study aimed to evaluate two different sets of secondary level English textbooks: "Exploring English" used in private schools under the Agha Khan Examination board and "Secondary Stage English" textbooks used in government schools of Sindh province in Pakistan. This study investigated whether these textbooks conformed to the objectives prescribed in the National Curriculum (2006) of Pakistan in terms of reading, writing, speaking, and grammar skills. The study adopted a modified checklist based on an adapted version of Cunningsworth's (1995) checklist to evaluate the textbooks and analyse the data. The results revealed that "Exploring English" textbooks are in greater conformity with the National curriculum 2006 compared to "Secondary Stage English" textbooks. "Exploring English" textbooks meet 75% objectives of reading and speaking skills and 65% objectives of writing and grammar skills, laid down in the national curriculum. On the other hand, "Secondary Stage English" textbooks match 50% objectives of grammar coverage, 30% objectives of reading and writing skills, and only 25% objectives of speaking skill. Specifically, "Secondary Stage English" textbooks do not comply fully with the objectives of the curriculum. The study highlights significant disparities in English language textbooks in public and private sector schools.