The study aimed at finding out the relationship between implementation of Safety Standards and Guidelines for Physical Infrastructure in public mixed boarding secondary schools in Nakuru County, Kenya. The study was guided by Invitational Theory by Purkey and Schmidt and Systems Theory by Von Bertalanffy. The target population was 16 principals, 18 deputy principals and 2130 Form 4 students drawn from all 16 public mixed boarding secondary schools in the county. The study adopted a descriptive survey design. The sample size comprised 327 Form 4 students. A census approach was used. . The population of the study was clustered into 9 sub counties. Stratified sampling technique was used to categorize the population into three strata namely principals, deputy principals and Form 4 students. The principals and deputy principals were selected using purposive sampling technique, while the students were selected using simple random sampling technique. Data from students was collected by use of questionnaires, while that from principals and deputy principals was collected using interview schedules. The researcher also used observation checklist to determine the level of implementation of the selected Safety Standards Guidelines in the schools. Prior to use, the instruments were subjected to validity checks with the help of university supervisors and reliability tests guided by the 0.7 Cronbach’s Alpha Reliability Coefficient level. Data analysis was done using tools in the SPSS version 22. Analysis involved computation of descriptive statistics: frequencies and percentages, and inferential statistics: Pearson Correlation and Regression coefficients. The data was then presented in tables and textually.