Background and Study Aim. Developing exercise programs to maintain the fitness and health of retired athletes is crucial as a preventive measure against common health problems in this population. Equally important is the creation of an exercise evaluation tool to assess the effectiveness of these programs. This study aims to test the validity and reliability of a physical fitness test instrument for retired martial arts athletes. Material and Methods. This study used an evaluation approach with data collected through tests and measurements. A total of 147 subjects participated. For validity testing, there were 35 retired male martial arts athletes and 37 retired female athletes. For reliability testing, there were 36 retired male and 39 retired female martial arts athletes. The instruments used included body mass index (BMI) measurements with digital scales, flexibility measurements with the sit-and-reach test, muscle strength measurements with a leg and back dynamometer, and cardiovascular endurance measurements with the Cooper test. Validity was assessed using a concurrent validity approach. Reliability was tested using the test-retest method. The Pearson product-moment correlation was used for validity analysis, while Cronbach's alpha was used to assess reliability. The JASP software was used for the analysis. Results. For male athletes, the r-values for each test item exceeded the r-table value of 0.275, confirming the validity of the body mass index (BMI), sit-and-reach test, leg and back dynamometers, and the Cooper test. Similarly, female athletes demonstrated r-values above the r-table value of 0.267, confirming the validity of all test items. The reliability of each item was confirmed by Cronbach’s alpha values, which were above the 0.7 threshold for both male and female athletes. The Cronbach's alpha value for BMI was 0.998 for both male and female athletes, indicating excellent reliability. Other test items, such as flexibility and muscle strength, also showed strong reliability, with Cronbach’s alpha values ranging from 0.742 to 0.985. Conclusions. The study highlights the importance of developing valid and reliable instruments to assess the physical fitness of retired martial arts athletes. Such instruments are essential for monitoring the effectiveness of training programs aimed at maintaining the health and fitness of retired athletes. The findings of this research confirm the value of structured fitness tests. These tests effectively evaluate key physical components such as body composition, flexibility, muscle strength, and cardiovascular endurance.