The present study aimed to analyze Cholinesterase (CE) levels in cord blood from preeclamptic women and to evaluate cholinesterase status in patients with osteosarcoma. Serum cholinesterase levels were assessed in 30 cases of osteosarcoma and 30 controls suffering from musculoskeletal pain. Additionally, maternal and cord blood samples were collected from 25 women with preeclampsia and compared with those from 25 normotensive pregnant women and 25 normal, healthy controls. The results indicated that serum cholinesterase levels were significantly lower in osteosarcoma patients (Group I) compared to those with musculoskeletal pain (Group II, p < 0.05). Similarly, cholinesterase levels were reduced in the maternal blood of women with preeclampsia when compared to normotensive controls. Cord blood cholinesterase levels were lower in the infants of normotensive mothers, with levels reaching 88.65% of the maternal levels. Furthermore, cord blood cholinesterase levels were significantly lower in preeclamptic women compared to normotensive pregnant women. When comparing cholinesterase levels to those of normal controls, it was observed that CE levels were significantly elevated in both normotensive and preeclamptic women. The findings of low serum cholinesterase levels in this study suggest that cholinesterase secreted by osteoblasts is utilized in bone formation and tumorigenesis. Additionally, the decrease in cholinesterase levels associated with preeclampsia may be linked to the loss of muscarinic cholinergic receptors that occur in this condition.