Groundwater quality of Chennai, Tamil Nadu (India) has been assessed during different seasons of year 2012. Three physical (pH, EC, and TDS) and four chemical parameters (Ca²⁺, Cl⁻, TH, Mg²⁺ and SO₄²⁻) from 18 bore wells were assessed. The results showed that pH of majority of groundwater samples indicates a slightly basic condition (7.99_post-monsoon and 8.35_pre-monsoon). TH was slightly hard [322.11 mg/l_pre-monsoon, 299.37 mg/l_post-monsoon but lies under World Health Organization (WHO) upper limit]. EC, TDS, Ca²⁺ and Mg²⁺ concentrations were under WHO permissible limit during post-monsoon (1503.42 μS/cm, 1009.37, 66.58 and 32.42 mg/l respectively) and pre-monsoon (1371.58 μS/cm, 946.84, 71.79 and 34.79 mg/l, respectively). EC shows a good correlation with SO₄²⁻ (R² = 0.59_pre-monsoon, 0.77_post-monsoon) which indicates that SO₄²⁻ plays a major role in EC of ground water of bore wells. SO₄²⁻ has also showed positive correlations with TDS (R² = 0.84_pre-monsoon, 0.95_post-monsoon) and TH (R² = 0.70_pre-monsoon, 0.75_post-monsoon). The principal component analysis (PCA)/factor analysis (FA) was carried out; Factor₁ explains 59.154 and 69.278 % of the total variance during pre- and post-monsoon, respectively, with a strong positive loading on Ca²⁺, Mg²⁺, SO₄²⁻, TDS and a negative loading on pH. Factor₂ accounts for 13.94 and 14.22 % of the total variance during pre- and post-monsoon, respectively, and was characterized by strong positive loading of only pH and poor/negative loading of EC, Ca²⁺, Mg²⁺, SO₄²⁻, TDS and TH during pre- and post-monsoon. We recommend routine monitoring and thorough treatment before consumption. Further, this study has demonstrated the effectiveness of PCA/FA to assess the hydrogeochemical processes governing the groundwater chemistry in the area.