We aim to clarify the impact of walking speed (WS) and analyze factors linked to WS decline in patients with chronic liver diseases (CLDs, 165 males and 191 females, 137 liver cirrhosis patients). The WS decline is defined as <0.8 m/second (m/s), referring to the guidelines. The median (range) WS was 1.3 m/s (0.2-2.02 m/s). There were 17 patients with WS <0.8 m/s (4.8%). The WS value was significantly correlated with the handgrip strength value both in males (r2 = 0.252, p < 0.0001) and females (r2 = 0.256, p < 0.0001). In the multivariate analysis of factors associated with WS decline, only the extracellular water (ECW) to total body water (TBW) ratio using bioimpedance analysis was an independent predictor (p = 0.0398). Extracellular fluid excess was categorized as follows: normal condition (ECW to TBW ratio <0.390), mild overhydrated condition (ECW to TBW ratio 0.390-0.399), and moderate to severe overhydrated condition (ECW to TBW ratio ≥0.400). The WS value was well stratified according to the ECW to TBW ratio (normal vs. mild, p = 0.0001; mild vs. moderate to severe, p < 0.0001; normal vs. moderate to severe, p < 0.0001; overall p-value <0.0001). In conclusion, the ECW to TBW ratio can be closely linked to WS decline in CLD patients.