To test the hypothesis that indicators and fluctuating asymmetry (FA) on fingers and palms in nonsyndromic cleft lip and/or palate (NSCL/P) and their parents were affected by developmental instability and to investigate a potential way for prenatal diagnosis of NSCL/P. Case-control study. West China College of Stomatology and Chengdu Children's Hospital, Chengdu, China. Three hundred sixty NSCL/P patients and their 720 unaffected parents were collected. Two hundred ninety normal children and their 580 parents were selected as the control. Total ridge counts, atd angle, fingerprints pattern types, a-b ridge count, and true pattern (TP) on palm were determined. For each indicator, asymmetry between hands was defined. Pattern types and asymmetries were statistically compared among groups. Compared with the control, NSCL/P patients had significantly greater a-b ridge count for both hands (P < .001), decreased TP in the left thenar area (TA) as well as in the hypothenar area (HA) and interdigital third area (I3) (all P < .05), and increased FA in HA and I3 (both P < .05), while their parents had greater a-b ridge counts (P < .001). NSCL/P patients possessed more slowly developing patterns and higher levels of FA on their palms, followed by their parents and then the controls. A-b ridge count could be a potential prenatal indicator in people without family history that are at increased risk of having a child with NSCL/P. The increased tendency for slower development of patterns and higher levels of FA indirectly support the possibility that the developmental sequence of ridges in NSCL/P is retarded. However, further work is still needed.