<![CDATA[Background: Kidney stones can impair urinary flow and may be accompanied by changes in renal-function markers. Stone size is routinely considered during clinical assessment, while serum creatinine provides information about renal excretory function. Their association in unilateral nephrolithiasis warrants investigation. Purpose: To examine the association between stone-size category and serum creatinine in patients with unilateral nephrolithiasis. Method: This retrospective cross-sectional study analyzed 92 medical records, purposively selected from a reported population of 120 patients at Dr. H. Abdul Moeloek Regional General Hospital, Lampung Province. Records from 2025 were reviewed in February 2026. Stone size was categorized as <5 mm, 5-10 mm, or >10 mm. Serum creatinine was recorded in mg/dL, and the association between stone-size category and serum creatinine was assessed using Spearman's rank correlation. Results: The sample included 51 men (55.4%) and 41 women (44.6%). Stones measured <5 mm in 52 patients (56.5%), 5–10 mm in 31 patients (33.7%), and >10 mm in 9 patients (9.8%). Mean serum creatinine was 1.61 mg/dL (range, 0.80–3.12). The stone-size category was significantly and positively associated with serum creatinine (rₛ = 0.732, p < 0.001). Conclusion: Higher stone-size categories were associated with higher serum creatinine in this hospital-based sample. The retrospective cross-sectional design and unadjusted analysis do not establish causality or an independent association.]]>
