The study was conducted to establish the Relationship between School Climate and Students’ Achievement of Government & Private Secondary Schools in the Province of Punjab. The instrument used in the study was organizational climate descriptive questionnaire (OCDQ) adapted by the researcher. The province of Punjab, Pakistan was divided into three strata i.e. Central Punjab, South Punjab and North Punjab. From each stratum 4, 2 and 1 districts, aggregating to 7 districts i.e. (20%) of the population was selected using stratified random sampling. The total number of sample was 792 teachers and principals from the selected, government and private secondary school of Punjab. SPSS 16 was used to analyze the data. To measure the differences, MANOVA was applied to compare the mean difference of all the sub-variables of principals’ behavior and teachers’ behavior aspect with respect to gender and sector. To measure students’ achievement, board secondary school examination results for the year 2012-2013 from all the selected schools were taken. Pearson correlation was applied to measure the degree of relationship of organizational climate and students’ achievement. The demographic details of the sample with respect to gender, sector and districts were: female representation was 50.2% of the total sample and male representation was 49.8%. Government sector representation was 50.5% as against 49.5% private sector representation. . The mean score and SD of government sector respondents was (3.86, 0.90) while the Mean and SD of private sector respondents was (3.51, 0.84). The analysis revealed that there was significant strong positive relationship between school climate and students’ achievement of government and private Secondary Schools in the Province of Punjab. Similarly the principals’ and teachers behavior aspects and all there sub-factors were also significantly correlated with students’ achievement.