Using hot water extraction, a large number of polysaccharides were obtained from Cucurbita maxima. A DEAE-Sepharose CL-6B chromatography column was used to isolate the major polysaccharides from C. maxima. Two fractions were obtained (LP2-1 and LP2-2). LP2-1 and LP2-2 consisted of neutral polysaccharides (MW: 1.02 × 104 and 4.32 × 108 g mol−1, respectively) comprised mainly of galactose units. Analyses by FT-IR spectrometry, partial acid hydrolysis, periodate oxidation, Smith degradation and GC-MS indicated that LP2-1 consisted of 85.3% (1→4) glycosidic linkages and 1.7% (1→3) or (1→6) glycosidic linkages. The LP2-1 backbone consisted of (1→4)-linked galactose units, which occasionally branched at O6 or O3. The branches were composed of (1→4)-linked galactose and terminated with galactose (13%). Two sulphated derivatives (SLP2-1 and SLP2-2) with variable degrees of sulphation (DS) were obtained by the sulphur trioxide–pyridine method, without degradation of the polysaccharide. DS of PL2-1 and PL2-2 was 0.19 and 0.20, respectively.