Air pollution from toxic materials is one of the world's health problems. The study was aimed to measure and analyze carbon monoxide (CO) exposure with oxygen saturation and work fatigue in parking attendants. The research method was quantitative research with cross sectional study approach that was the measurement of variables carried out simultaneously. The non-random sampling method of sampling with total sampling technique that all parking attendants on the Setiabudi street in Semarang City. The number of research subjects was 30 people. The results showed that as much as 26.7% with abnormal CO exposure, 70.0% abnormal oxygen saturation, 56.7% of the study subjects experienced moderate fatigue and 43.3% mild fatigue. The results of bivariate analysis showed that CO exposure not normal with abnormal oxygen saturation 75.0%, while normal CO exposure with abnormal oxygen saturation 62.8%, statistical test results obtained p value = 1,000. Analysis of abnormal CO exposure with moderate work fatigue 25.0%, while normal CO exposure with moderate work fatigue 68.2%, statistical test results obtained p value = 0.035. It was concluded that CO exposure was not associated with oxygen saturation and CO exposure had a significant associated with work fatigue.Keywords; CO exposure, work fatigue, oxygen saturationAbstrakPencemaran udara yang berasal dari bahan toksik merupakan salah satu masalah kesehatan dunia. Penelitian ini bertujuan untuk mengukur dan menganalisis paparan karbon monooksida (CO) terhadap saturasi oksigen dan kelelahan kerja pada petugas parkir. Metode penelitian adalah penelitian kuantitatif dengan pendekatan cross sectional study yakni pengukuran variabel dilakukan secara bersamaan. Metode pengambilan sampel non random sampling dengan tekhnik total sampling yakni seluruh petugas parkir di jalan Setiabudi Kota Semarang. Jumlah subjek penelitian sebanyak 30 orang. Hasil penelitian menunjukkan sebanyak 26,7% dengan paparan CO tidak normal, 70,0% saturasi oksigen tidak normal, 56,7% subjek penelitian mengalami kelelahan sedang dan 43,3% kelelahan ringan. Hasil analisis bivariat menunjukkan bahwa paparan CO tidak normal dengan saturasi oksigen tidak normal 75,0%, sementara paparan CO normal dengan saturasi oksigen tidak normal sebanyak 62,8%, hasil uji statistic diperoleh nilai p value = 1,000. Analisis paparan CO tidak normal dengan kelelahan kerja sedang 25,0%, sementara paparan CO normal dengan tingkat kelelahan kerja sedang 68,2%, hasil uji statistic diperoleh nilai p value = 0,035. Disimpulkan bahwa paparan CO tidak berhubungan dengan saturasi oksigen dan paparan CO memiliki hubungan signifikan dengan kelelahan kerja.Kata kunci; kelelahan kerja, paparan CO, saturasi oksigen