Aim: To compare the clinical parameters, glycemic status [glycated hemoglobin (HbA1c)], and full mouth scaling and root planing (FMSRP) with conventional staged scaling and root planing (CSSRP) in subjects with generalized chronic periodontitis (GCP) and type 2 diabetes mellitus (T2DM) administering doxycycline as a systemic antibiotic. Materials and methods: A total of 30 patients consisting of 15 subjects each in group I and group II with GCP [clinical attachment loss (CAL) of ≥3 mm observed in >30% of the teeth] with T2DM (HbA1c level of ≥7%) receiving FMSRP for group I in <24 hours with systemic doxycycline 100 mg for 14 days and group II undertaking systemic doxycycline 100 mg (CSSRP) for 14 days and receiving CSSRP in 21 days were taken into consideration. Both the groups underwent periodontal assessment of the variables, such as CAL, plaque index (PI), bleeding index (BI), probing depth (PD), and HbA1c on 0 day (baseline), 3rd, and 6th month. Results: Intragroup and intergroup comparisons of PI, BI, PD, CAL, and HbA1c scores between groups I and II, showed that the reduction was greater in group I (FMSRP group) compared to group II (CSSRP) at every standardized and designated time point (p < 0.001). Intergroup comparison of HbA1c also turned out to be significant at various time points (p < 0.001). Conclusion: Full mouth scaling and root planing (FMSRP) with doxycycline provides a valuable treatment option along with better glycemic control in treating GCP in subjects having T2DM. Clinical significance: The present study has been done to check the significance of periodontal treatment with respect to “FMSRP” on the metabolic aspects of DM patients with chronic periodontitis disease so as to emphasize the importance of periodontal health maintenance in these patients.