The study primarily explored the impact of Learning Organization’s Practices (LOPs) on Employee Performance (EP) by examining the mediating roles of Employee Engagement (EE) and Employee Development (ED) in Pakistan’s Telecommunication Sector Organizations (PTSOs). It also examined the moderating role of Performance Appraisal Justice (PAJ) between the relationships of LOPs and EE and LOPs and ED in PTSOs. The study addressed the four research questions on PTSOs, covering; the impact of LOPs upon EP, impact of LOP’s on EP mediated through the path of ED and EE, Performance Appraisal Justice moderating the relationship between LOPs and Employee Engagement, and Performance Appraisal Justice moderating the relationship between LOPs and Employee Development. The hypotheses of the study included the significant impact of Learning Organization Practices on Employee Performance, Employee Engagement, and Employee Development. They also included the significant impact of Employee Engagement on Employee Performance, the significant impact of Employee Development on Employee Performance, the Relationship between LOPs and Employee Performance mediated through Employee Development and Employee Engagement, Performance Appraisal Justice moderating the relationship between Learning Organization Practices and Employee Engagement, and Performance Appraisal Justice moderating the relationship between Learning Organization Practices and Employee Development. VIIIThe study used quantitative approach using self-administered questionnaires. The questionnaire was built on the eight existing standardized questionnaires taken from; DLOQ, Marsick and Watkins (2003), CIPD (2006), Oreg and Nov (2008), Pinchuk (2010), Medlin and Green (2009), Muhammed (2006) and Gupta and Kumar (2013). Eight demographic questions have also been included in the second section of the study questionnaire. Instruments of the study were validated by factor analysis. The study included the data collected from 1228 respondents in PTSOs. All the relationships were tested using correlation and Structure Equation Modeling (SEM). The SEM indicated multiple confirmations like; LOPs had a strong impact on EP and on EE (Fig 7), LOPs did have a strong impact on ED, EE had an impact on EP, ED had a strong impact on EP. All of these indicated a significant path coefficient. Results also confirmed that Employee Engagement and Employee Development mediated the relationship between Learning Organization Practices and Employee Performance. Results drawn from SEM using the extracted significant path coefficient confirmed that the relationship between LOPs and Employee Performance was also mediated by both EE and ED together. Finally the moderation results extracted from SEM indicated that PAJ moderated the relationships between LOPs and EE, and LOPs and ED. The study divulged a new track for the researchers and practitioners of LOs. The sequence of measures have to be taken into consideration by the LOs, revealed from the current study i.e. 1) the provision of LOs first have to be ensured in the organizations to LOs in the right manner, 2) looking at the impact IXof LOPs upon their employees’ engagement states, 3) analyzing the impact of implemented LOPs on ED states, and 3) checking their performance appraisal system is bias- free performance appraisal system which should possess the said four justice types. Keywords: Learning Organizations, Learning Organization Practices, Employee Engagement, Employee Development, Performance Appraisal Justice, Employee Performance