Although appetite and its disorders have been implicated in disease progression and outcomes, ghrelin concentrations, an objective appetite measure, are rarely assessed in patients with gynecological malignancies. The present study aimed to assess changes in post-operative versus pre-operative appetite levels in patients with gynecological cancers scheduled for tumor removal surgery (N = 53). Acylated ghrelin concentrations were assessed as an objective appetite proxy, whereas the Council of Nutrition appetite questionnaire (CNAQ) was employed as a subjective appetite measure. Ghrelin concentrations were increased post-operatively (median: 12.1 pg/mL, IQR: 0.67 to 23.5, -value = 0.001) but the perceived appetite of patients (CNAQ) remained unchanged (median: -1, IQR: -3 to 1). Tumor removal surgery decreased all anthropometric indices (body weight, body mass index, waist and hips circumferences, triceps skinfolds, body fat, fat mass and fat mass index, -value ≤ 0.001 for all) and doubled the risk of malnutrition among patients. No difference was recorded in the change in participants' objective and subjective appetite when they were classified according to the tumor type. No correlation was observed between ghrelin concentrations and CNAQ score pre-operatively (Spearman's rho correlation coefficient = -0.181, -value = 0.298) or post-operatively (Spearman's rho correlation coefficient = 0.071, -value = 0.684). The observed post-operative rise in ghrelin concentrations is associated with body weight loss and consists of a possible defense mechanism of the human body, aiming to prolong survival.