Background <p>Oxaliplatin frequently causes chemotherapy-induced peripheral neuropathy (CIPN), including impaired hand dexterity; however, factors associated with dexterity impairment remain unclear. This study aimed to compare hand function, dexterity, strength, and pain according to neuropathy severity, and to identify factors associated with impaired hand dexterity.</p> Methods <p>A total of 206 patients received oxaliplatin-based chemotherapy, of whom 102 (49.5%) developed CIPN and were included in this cross-sectional study. All participants were aged ≥ 40 years and had received at least three cycles of oxaliplatin-based chemotherapy at a tertiary research hospital. Neuropathy severity was classified according to the National Cancer Institute Common Terminology Criteria for Adverse Events as Grade (I-III). Outcome measures included grip strength measured with a hand dynamometer, pinch strength assessed with a pinch meter, fine motor skills and hand dexterity evaluated using the Minnesota Manual Dexterity Test (MMDT) and Nine-Hole Peg Test (NHPT), hand function assessed using the Michigan Hand Outcomes Questionnaire (MHOQ), pain intensity measured with the PainDETECT Questionnaire, and CIPN symptoms evaluated using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire–Chemotherapy-Induced Peripheral Neuropathy 20 (EORTC QLQ-CIPN20). Group comparisons were performed using one-way ANOVA or Kruskal–Wallis tests with Tukey or Dunn post-hoc analyses, respectively. Ordinal logistic regression (complementary log-log link) identified predictors of neuropathy severity, while multiple linear regression analyses assessed factors associated with hand dexterity.</p> Results <p>Significant between-group differences were observed in grip and pinch strength, hand dexterity performance, MHOQ subparameters, CIPN20 scores, and PainDETECT scores (<i>p</i> &lt; 0.05). Neuropathy severity was significantly associated with cumulative oxaliplatin dose and gender (<i>p</i> &lt; 0.05), with higher cumulative doses increasing the risk of severe neuropathy. Regression analyses demonstrated that grip strength, gender, and CIPN20 motor scores were significant predictors of hand dexterity performance in both MMDT placing and turning models (<i>p</i> &lt; 0.001). Lower grip strength and higher motor neuropathy scores were associated with poorer dexterity performance.</p> Conclusion <p>Increasing neuropathy severity was associated with poorer hand function, reduced strength, and impaired manual dexterity. Cumulative oxaliplatin dose and sex were significant predictors of neuropathy severity, whereas grip strength and motor neuropathy symptoms were important determinants of hand dexterity performance.</p> Trial registration <p>ClinicalTrials.gov NCT07203066, registered on 24 September 2025.</p>