Periodontal diseases are among the six most prevalent non-communicable diseases (NCDs) worldwide, constituting a burden for oral and general health. There is a shortage of epidemiological data on periodontal diseases in Africa. The aim of the present cross-sectional study was to present the periodontal status and cotinine levels of a South African population of adults. This study included individuals living in the Belville South area. Bleeding on probing (BOP) and pocket depth were recorded for each tooth, and clinical attachment loss (CAL) was recorded as the highest score per sextant. Cotinine levels were measured in ng/mL. A total of 951 individuals were included. More than one third of all subjects had BOP. Regarding pocket depth, over 50% of the subjects had shallow pockets (4–5 mm), and almost 6% had deep pockets. CAL ≥ 4 mm was present in 40.1% of the subjects. Males presented worse periodontal conditions than females. In total, 52.7% of the participants had serum cotinine levels of ≥15 ng/mL. Cotinine levels had no effect on periodontal variables. Periodontal diseases were highly prevalent, and periodontal conditions were worse in males. Preventive and restorative public health programs are required to improve oral health in this population.