Vygotsky believed that children’s best learning takes place within their zone of proximal development (ZPD), a range of tasks too difficult for the child to do alone but possible with the help of adults and more skilled peers. Vygotskian theory adheres to the significance of dialogue as an avenue by which individuals negotiate conceptual change. The formulations of Vygotsky lead us to believe that learning environment for children should involve guided interaction and they should change their conceptions through social interaction, speech, and communication. For this reason, it is anticipated that students who are not performing well in a subject due to their misconceptions will show improvement upon being scaffolded and tutored by a more skilled person. It is important x that the peer and adult tutor verbalizes the problem solving process to help the tutee in learning and understanding. The use of peer tutoring across many disciplines is increasing to help in engaging students for effective learning process. It is generously recognized that educational outcomes in academic, social, emotional and moral domains of learning are related with students engagement. When they become actively involved in their learning and the chances for them to perform better increase. The use of peer tutorials enhance students interest and sharpens their academic skills is indicated by a wealth of research in this field. Peer plays a special role in children’s development in addition to parents and teachers. However, the greater fluidity, freedom and equality of peer relationships offers children the opportunity for a new kind of interpersonal experimentation and exploration. In particular, it stimulates a new sensitivity that forms a cornerstone for the development of social competence, a sense of social justice, and the capacity to form relationships with others outside the family. This piece of experimental research was guided by Lev Vygotsky’s ideas on social interaction through scaffolding by peers within each learner’s ZPD. Peer tutoring strategy was implemented to examine its effects on the achievement and attitude of students in the subject of English. The objectives of the study were to measure the achievement of the students in the subject of English before the experiment , to expose the experimental group to peer tutoring and the control group to conventional teaching to compare the difference in the achievement of students participating in peer tutorials and students who did not participate in peer tutoring. It was hypothesized that there would be significant difference between mean achievement scores of the students taught through peer tutoring and those taught through traditional teaching. The population of the study consisted of the 4086 girl students of 9th class studying English as a subject in 12 Federal Secondary Girls Schools of Wah Cantt (Pakistan). A sample of 60 students was taken from one randomly selected girl school out of 12 Federal Girls secondary schools. The design of the experimental study was “Pretest-Posttest Nonequivalent Groups Design” which is a form of Quasi-Experimental designs. 90 students from three sections out of six sections of 9th class in the selected school were pretested through a self developed achievement test. On the basis of pre- test results and the willingness of the students, 30 students from two sections were assigned to the experimental group to be treated through peer tutoring. While students of third section were assigned to the control group. Moreover, 30 peer tutors were selected from 10th class of the same school on the basis of the pretest results and their willingness to serve as tutors. The duration of the study was six weeks. To determine the significance of the tutoring intervention through comparison of pre- and post-test achievement of experimental and control groups, descriptive statistics of mean, median, SD, coefficient of variation, and inferential statistics of t-test and ANCOVA were used. xii The study results indicated that the experimental group showed greater improvement in their English achievement as a result of their exposure to peer tutoring. Peer tutoring had thus a visible effect on the posttest performance of the experiment group when tested at .05 level of significance. Further studies need to investigate the effect of peer tutoring strategy on socioemotional aspects of learning and development in addition to its impact on cognitive learning and development.