The current Kenyan secondary English curriculum (2002) has adopted an integrated approach not only to teaching, but also to the assessment of English language and Literature. This re-organisation is meant to improve the standards of teaching and performance in English. However, national performance in integrated English has remained consistently below average, contrary to expectations. This paper is based on a research that was conducted in Nairobi North sub-county, Nairobi County, Kenya on "The Promise of Integrated English: Teachers' and Head teachers' Reactions and Reflections." The study mainly used a qualitative approach and employed questionnaires, interview and observation schedules to collect data from 101 teachers of integrated English and 20 head teachers. Further, the heads of English at Kenya Institute of Curriculum Development, Directorate of Quality Assurance and Standards and Kenya National Examinations Council were interviewed. Raw data collected from questionnaires, interview and observation schedules were organized into significant patterns so as to easily interpret and understand the essence of the data. The study revealed that despite the promise of the re-organized English curriculum, teachers were teaching the integrated English curriculum without proper understanding of the methodology involved. Consequently, they faced difficulties and resorted to teaching English language and Literature as two separate subjects. The study concluded that there has been no effective implementation of integrated English curriculum in Nairobi North sub-county as was/is intended by the curriculum developers. The study recommends proper and continuing professional support to the teachers of integrated English curriculum in the form of in-service training for the promise to hold.