Objective: To determine whether the assessment of umbilical cord diameter (UCD) is a viable indicator of fetal growth and perinatal outcome. Material and Methods: A total of 652 singleton pregnancies between 10 and 40 weeks of gestation were reviewed for this study. The UCD was measured vertically in the longitudinal section, adjacent to its insertion at the fetal abdomen. Other fetal biometrics were measured according to standard measurement protocols. The perinatal outcome of each patient case was also recorded. Result: The UCD ranged between 0.73 and 1.68 cm, and correlated positively with gestational age, estimated fetal weight ( r = 0.779, r = 0.639, P < .05), and other fetal biometrics. The UCD of 50 subjects was 2 standard deviations below the mean and correlated significantly ( r = 0.712, P < .05) with poor fetal outcome in the first and second trimester. Observational studies of 50 subjects, whose UCD was 2 standard deviations below the mean, resulted in 21 cases of intrauterine fetal death, 10 cases of preeclampsia, 8 cases of oligohydramnios, and 11 cases of intrauterine growth restriction. Conclusion: The UCD has the potential to serve as an important indicator of fetal growth, well-being, and perinatal outcome.