This study examines the key financial factors influencing the capital structure decisions of firms operating in Türkiye’s maritime maintenance sector. Using a panel dataset covering the 2010–2022 period, financial indicators of 190 firms were analyzed. The model was estimated using the random-effects (RE) estimator, incorporating firm-level clustered robust standard errors to guarantee statistical reliability and consistency. The findings reveal that the current ratio, return on assets, interest coverage ratio, and firm size have negative and statistically significant effects on leverage. This indicates that firms with higher liquidity and profitability tend to rely more on internal financing rather than external debt. In contrast, the financial expenses-to-sales ratio and total debt-to-equity ratio were found to have no significant impact on leverage decisions. These results suggest that, under the conditions of high inflation, exchange rate volatility, and fluctuating credit costs in Turkey during the 2010–2022 period, firms adopted a cautious borrowing strategy. Overall, the findings are consistent with the Pecking Order Theory, indicating that maritime maintenance firms prioritize internal financing, maintain conservative leverage levels, and avoid excessive debt risk. This financing behavior aligns with the capital-intensive nature, long investment cycles, and high funding costs characteristic of the maritime maintenance industry.