Implication of the tumor size on oncological and functional outcomes of craniopharyngioma is inconsistently reported. The aim of this study is to assess the postoperative outcome of giant craniopharyngiomas (> 4 cm in diameter) and to elucidate the impact of tumor size on various outcome parameters and survival. Forty-four patients (children aged ≤ 18 years: 25; adults: 16) with giant craniopharyngioma, operated between January 2001 and December 2015, were included in this study. Various outcomes, progression-free survival (PFS) and overall survival (OS) were calculated. Gross total resection (GTR) was achieved in 17 (39%) and subtotal resection (STR) in 27 (61%) patients. Eleven patients (25%) received radiotherapy (RT) after STR. Postoperatively, new cranial nerve and motor deficits were noted in 12 (27%) and 9 (20%) patients, respectively. Tumor recurrence following GTR and STR without adjuvant RT was diagnosed in 3 (17%), and 5 (38%) patients, respectively. Following STR with RT, one (9%) experienced recurrence. PFS at 5-, and 10- year following GTR, STR, and STR + RT was 80.8%, 45.4%, and 90%, respectively. At 5- and 10- year, OS was 86.5%, 77.9% and 100% following GTR, STR, and STR + RT, respectively. The rate of GTR was significantly lower in patients with giant tumors (39% vs. 62%; Chi-square test, p value 0.008). Postoperatively, neurological deficit (20%), hypopituitarism (95%) and hypothalamic dysfunction (26%) were significantly higher for giant craniopharyngiomas. Hazards of recurrence were not significant between giant and non-giant tumors (hazard ratio 1.86; 95% CI 0.94–3.68; p 0.07). There was no significant difference in OS between the patients with giant and non-giant tumors (log-rank test 2.1; p value 0.14). Tumor size should be considered as an important predictor of the postoperative functional outcome. Although the rate of GTR is less than that of small tumors, the recurrence rate, progression-free survival, and overall survival of the patients with giant tumor are comparable to non-giant tumors.