The study was conducted to determine the role of dry matter and total soluble solids (TSS) as quality indicators in the assessment of pumpkins (Thong Lanna (TL) 2, TL7, TL11, TL17, and commercial cultivar (CC)). Pumpkins were categorized into two groups, sticky (TL11, TL17, and CC) and less sticky (TL2 and TL7), based on their adhesiveness value, wherein the adhesiveness had a highly negative association with amylose content. On the other hand, the starch content showed a highly positive association to amylose content. Less sticky pumpkins that contained high dry matter and total soluble solids (TSS) exhibited a high antioxidant (total flavonoid contents and total carotenoids) and antioxidant capacity (2,2-diphenyl-2-picryl-hydrazyl (DPPH) and ferric reducing antioxidant power (FRAP). The other traits observed in less sticky pumpkins were lower fruit weight and pulp firmness, and higher sweeter pulps and starch content than sticky pumpkins. A pumpkin with a high dry matter and TSS showed a low adhesiveness value. Moreover, the shape and sizes of starch granules did not indicate the stickiness of cooked pulp. Therefore, dry matter and TSS could be used to rapidly determine antioxidant capacity in these pumpkins, which would be convenient, whereas amylose content is for the stickiness of cooked pulp.