The quality of posture and the level of general physical performance rank among the most important factors of health-related fitness as they enhance the quality of life and promote the health of pupils. The aim of the research was to determine the level of health-oriented fitness in terms of general physical performance and general posture in pupils as well as to broaden the existing knowledge related to these issues. The sample consisted of a total of N = 191 pupils of late school age, including 95 male and 96 female pupils, who attended primary schools in Central Slovakia. The mean age of male pupils was 12.3 ± 0.47 years, their mean body height was 155.36 ± 9.54 cm and the mean body weight was 54.28 ± 9.27 kg. The mean age of female students was 12.2 ± 0.35 years, with a body height of 154.71 ± 6.53 cm and a body weight of 48.74 ± 6.59 kg. When it comes to data collection methods, we used standardized methods for physical education practice and we focused on primary somatometry, general posture and general physical performance. Our findings showed the prevalence of overall qualitative level III, which is characterized as “bad body posture”, both in male and female students. The boys had significantly worse results than the girls. We did not find any significant differences when it comes to general physical performance. In both genders, however, the tests confirmed a decline in endurance performance, which is important for pupils’ health and fitness. We found significantly better results in female pupils when it comes to seated forward bend and pull-up holds. The boys, on the other hand, performed better in the long jump, 30-s sit-ups and 5 × 10 m shuttle run. Our findings should be perceived in a broader context of pupils’ physical health and overall readiness of their bodies for daily stress.