The aim of this study was to examine the prevalence and relationship between periodontal disease and pre-term low birth weight (PLBW) among Saudi mothers at King Khalid University Hospital (KKUH) in Riyadh, Saudi Arabia. The periodontal status and the relative risk were also analyzed. The study consisted of 30 cases [infants <37 weeks and/or weighing <2.500 kilograms (kg)] and a daily random sample of 60 controls [> 37 weeks and/or weighing >2.500 kg]. Clinical periodontal indices were measured on the labor wards. Associated risk factors for periodontal disease and PLBW were ascertained by means of a structured questionnaire and maternal notes. The prevalence of the PLBW was found to be 11.3%, and the prevalence of periodontal disease was high among the study population. The risk of PLBW remained high with increasing periodontal disease (odds ratio [OR] 4.21, 95% confident interval [CI] 1.99-8.93) despite controlling the other risk factors such as age, smoking, and social class. In conclusion, there is a correlation between periodontal disease and PLBW in KKUH.