The position of the moon in its orbit at different phases of lunar month affects the human physiological functions. The purpose of the study was to explore the blood glucose level and autonomic functions by measuring resting heart rate and blood pressure in four specific phases of the lunar month in type 2 diabetic patients. The study was conducted on 40 randomly selected patients (21 males and 19 females) from Diabetes Clinic of Calcutta Medical College in four phases such as new moon (NM), first quarter (FQ), full moon (FM) and third quarter (TQ) of lunar month. Plasma glucose level of each subject was estimated by colorimetric end point test method. After overnight fasting, 3ml of venous blood sample was collected from each subject in ethylenediaminetetraaceticacid (EDTA) vacutainer. Then plasma was separated (by centrifugation at 3000 revolutions per minute for 10 minutes) and glucose concentration was measured using commercially available kit [Lab Care Diagnostics (India) Pvt. Ltd., India, Catalog No: GLU 500]. Blood pressure and heart rate of each patient were measured manually at rest and during static exercise in four lunar phases. Static exercise, in terms of hand grip strength, was performed using hand grip dynamometer (Lafco India Scientific industries, Ambala 133001, Haryana). The patients were asked to pull the handle maximally, hold the dynamometer at least for 5 seconds, and blood pressure and heart rate were recorded steadily during that period. The protocol and procedures employed were in accordance with the human ethical guidelines of the Institutional Human Ethical Committee, Institute of Post Graduate Medical Education and Research (IPGMER) and Seth Sukhlal Karnani Memorial Hospital (SSKM) (Ref. No. IHEC/SDC/P12/18 dated 16.03.2018). The fasting plasma glucose levels in NM and FM were significantly higher (p<0.001) than that in TQ and FQ for both males and females. The mean values of resting systolic blood pressure (RSBP) and resting heart rate (RHR) for both males and females were significantly higher in NM and FM than that in FQ (p<0.05) and TQ (p<0.05). Similarly, the mean values of systolic blood pressure (EXSBP) and heart rate during static exercise (EXHR) for both males and females were significantly higher in NM and FM than that in FQ (p<0.01) and TQ (p<0.01). It appears from this study that there is a circalunar periodicity of blood glucose level and autonomic neural activity for type 2 diabetic patients which is efficiently adjusted during NM and FM in comparison to FQ and TQ. So the lunar phase is a factor that should be taken into concern when preparing or analyzing the data of autonomic neural activity for a type 2 diabetic patient.