Overweight or obesity is currently a common health problem in westernized societies globally. Obesity is linked with a sizeable number of disease aetiologies, notably type-2 diabetes, cardiovascular disorders and certain cancers, perhaps through some common mechanisms that favor persistent low-grade inflammation. Both epidemiological and laboratory studies have demonstrated that the pathogenesis of certain cancers and the related prognosis are influenced by obesity. Clinically, a complex situation is present in obesity, which usually shows higher blood levels of various biomolecules, e.g., lipids like triglycerides, hormones like insulin, and fat cell-secreted adipokines like leptin. On the contrary, obesity is associated with lower concentrations of substances like sex hormone-binding globulin and adiponectin. Many of these biochemical compounds are used routinely for clinical diagnosis and assessment during the follow-up period. Nonetheless, approximately one-fifth of the total cancer burden is associated with obesity. Excess adipose tissue and different hormonal substances possibly play a significant role in this complex obesity-related carcinogenesis. A precise understanding of the pertinent pathological processes is definitely useful in early diagnosis, clinical management, and designing of novel pharmaceutical agents.