Background: There are many studies on the pattern and incidence of cancer, but there are few documented works on cancer mortality (CM). Even fewer are African studies on CM that encompass all cancers and reveal the relative contributions of the various cancers to the overall burden of CM. This retrospective study was therefore performed to determine the types and patterns of cancer deaths in Nnamdi Azikiwe University Teaching Hospital, Nnewi, Southeast, Nigeria, during the 10-year period from 2010 to 2019. Materials and Methods: Data were collected from the death data files in the mortuary unit of the department of anatomic pathology. These death data document the cause of death as issued by the attending medical/surgical/oncology teams or the pathologist that performed an autopsy on the deceased. Data collected included the deceased's age, sex, and underlying cause and date of death. Results: One thousand one hundred and sixty-six deaths (representing 10.3% of all hospital deaths) were due to cancers. There were 472 (40.5%) males and 694 (59.5%) females in the series (P < 0.001), giving a male-to-female ratio of 1:1.5. The mean age for males was 53.2 ± 22.6 years and that of females was 48.3 ± 17.9 years. A bimodal age distribution pattern of CM was noticed with peaks in the 0–10-year and 51–60-year age groups (P < 0.001). The second peak occurs a decade earlier in females (51–60 years) than in males (61–70 years). In terms of type, breast, liver, and hematological malignancies were among the top three causes of cancer deaths. Cancers of the breast, liver, hematolymphoid tissues, ovary, and cervix were the largest contributors to the cancer-associated mortality burden among females. Prostate, liver, hematological, pancreas, and colorectal malignancies were the leading cause of CM among males. Hematological malignancies resulted in the death of more children and young adults younger than 31 years. Breast and liver cancers accounted for the most cancer deaths that affected patients in the 31–60-year-old age group, while deaths due to prostate cancer predominated in those above 60 years of age. Conclusion: Cancers have remained a vital cause of mortality in our setting. Screening for premalignant lesions, early detection, and treatment of cancers are therefore keys to improving dismal outcomes.