Objective: To investigate the possible effects of isolated fetal choroid plexus cysts (CPCs) on middle cerebral artery (MCA) Doppler parameters. Material and Methods: A total of 113 pregnant women at 18 to 22 gestational weeks in whom level 2 ultrasonography (USG) was performed between August 2017 and January 2018 were included in the study. Fifty-five women (CPC group) had isolated fetal CPC, whereas 58 women (control group) had no fetal structural anomaly. We measured the following MCA Doppler parameters of fetuses: peak systolic velocity (PSV), end-diastolic velocity (EDV), the systolic/diastolic ratio (S/D), pulsatility index (PI), and resistance index (RI). We examined whether a significant difference exist between the CPC and control groups, and between the CPC and contralateral sides with respect to the Doppler parameters. Results: We found that cysts were present in the right lateral ventricle in 49.1% (n=27) individuals in the CPC group. There was no statistically significant difference between the groups in terms of PSV, EDV, PI and RI values; however, the S/D ratio exhibited statistical significance. The MCA S/D ratio of the control group was lower than that of the values reported for both cystic and contralateral sides in the CPC group. Moreover, we did not observe any significant difference in S/D ratios between the cystic and contralateral sides in the CPC group. Conclusion: Isolated fetal CPCs tend to occur more on the right side unilaterally. At 18 to 22 weeks of gestation, MCA S/D ratios of the cystic and contralateral sides in the CPC group were higher than that in the control group. [ABSTRACT FROM AUTHOR]