Data about functioning capability of schools and students’ achievement is collected through program monitoring and implementation unit (PMIU). It shows satisfactory trends about the performance of schools and students’ achievement scores in PEC exam. But, its correctness is questionable in many aspects because of having no auditing system or third-party validation. This paper investigates the influence of district ranking system on students’ achievement score in PEC exam by using cheating in PEC exam as a mediator. The data were collected from 300 students who recently passed PEC exam from 10 schools by using a questionnaire developed by the researchers. 10 focus group interviews were also conducted from teachers of these schools. Hence mixed method approach was used in this study. Data was analyzed in SPSS and PROCESS. The results of the study reveal that district ranking system has significant positive influence on students’ achievement score in PEC exam. District ranking system also has significant positive impact on cheating in PEC exam. Furthermore, cheating in PEC exam partially mediates the relationship between district ranking system and students’ achievement score. The results suggest that quantitative target achieving behavior overlooks other important aspect of schools’ performance and focus only on few indicators. Additionally, monitoring system and PEC assessment system have failed to provide accurate, valid, reliable, trustworthy and practical data over school and students’ performance. These performance measuring systems need consistent audit and third-party validation to ensure the correctness of data.