Pancreatic cancer (PC) has the highest frequency of developing cancer cachexia (CC)–sarcopenia (SC) syndrome, which negatively influences patients’ outcome, quality of life, and tolerance/response to treatments. However, the clinical impacts of CC, SC, and their associated factors on outcomes for advanced PC has yet to be fully investigated. A total of 232 patients were enrolled in this study for the retrospective review of their clinical information and the measurement of skeletal muscle areas at the third lumber vertebra by computed tomography scan to identify CC or SC. The association and concurrent occurrence of clinicopathological features in each patient, prevalence rates, and prognosis with the CC or SC were calculated. CC and SC were observed in 83.6% (n = 194) and 49.1% (n = 114) of PC patients, respectively. Low hemoglobin levels more often occurred in CC patients than in non-CC patients (p = 0.014). Older age (p = 0.000), female gender (p = 0.024), low body mass index (BMI) values (p = 0.004), low hemoglobin levels (p = 0.036), and low albumin levels (p = 0.001) were more often found in SC patients than in non-SC patients. Univariate and multivariate analyses showed that CC was an independent poor prognostic factor of overall survival (OS) and progression-free survival for all patients, the chemotherapy (C/T) subgroup, and the high BMI subgroup. Meanwhile, SC was an independent predictor of poor OS for the subgroups of C/T or high BMI but not for all patients. These findings reveal the clinical differences for CC and SC and provide useful information for predicting the prognosis of advanced PC patients and conducting personalized medicine.