Abstract: In the present study, several microbiological and physicochemical properties of the potable/utility water in central Afyonkarahisar and its counties were investigated. A total of 162 potable/utility water samples collected in June to August 2011 were used as the study material. Drop plate method was used for Total Aerobic Mesophilic Bacterial (TAMB) counts and psychrotrophic microorganism counts whereas membrane filtration method was used in the identification of Pseudomonas sp., enterobacteria, enterococcus, coliform bacteria, E. coli and Cl. perfringens. The microbiological findings of the study indicated that the total aerobic mesophilic bacterial counts in wells were <1 cfu/100 mL in 32% of all samples and <1cfu/250 mL in utility and spring-tap water samples. The aerobic bacterial count was 1-10 cfu/250 mL in 35% of the utility water samples, 11-100 cfu/250 mL in 24% and 101-300 cfu/250 mL in 9% whereas it was 1-10 cfu/250 mL in 56% of spring/tap water samples and 11-100 cfu/250 mL in 7% in addition to the fact that no samples were identified to have bacterial counts in the range of 101-300 cfu/250 mL. The well water bacterial count was determined as 1-10 cfu/250 mL in 46% of the samples, 11-100 cfu/250 mL in 15% of the samples and 101-300 cfu/250 mL in 11% of the samples. The psychrotrophic organism count was determined as <1 cfu/100 mL in well water samples and <1 cfu/250 mL in spring/tap water samples in 40% of the cases. The aerobic microorganism count was determined as 1-10 cfu/250 mL in 41% of the utility water samples as 11-100 cfu/250 mL in 13% and 101-300 cfu/250 mL in 7% whereas the aerobic microorganism count was determined as 1-10 cfu/250 mL in 50% of the spring/tap water samples and as 11-100 cfu/250 mL in 6% in addition to <1 cfu/250 mL in 101-300 cfu/250 mL range. The well water samples were determined to have 1-10 cfu/100 mL of aerobic microorganisms in 41% of the samples, 11-100 cfu/100 mL in 17% of the samples and 101-300 cfu/100 mL in 7% of the samples. The water samples (utility/spring-well water) collected from Afyonkarahisar and its provinces were determined to be contaminated by coliform bacteria (17%, 28 samples), enterobacteria (15%, 24 samples), enterococcus bacteria (12%, 20 samples), E. coli (7%, 12 samples), Pseudomonas sp. (13%, 21 samples) and sulfite reducing microorganisms-Cl. perfringens (14%, 23 samples) in the study. All the samples under investigation were determined to be clear, odorless with specific taste and color although some samples did not comply with the legislation in terms of the microbiological criteria. The results of the physicochemical analysis indicated that the average pH, turbidity (NTU), conductivity (μohm/cm) and total hardness (French Hardness Degree, f⁰) values of the 162 samples were 7.28; 0.497; 362.11; 22.78, respectively. The average nitrite, nitrate, arsenic, chlorine, ammonium, floride, calcium and sulfate concentrations of the samples were determined as 0.09 mg L^-1, 17.25 mg L^-1, 0.26 μg L^-1, 0.83 μg L^-1, 0.15 mg L^-1, 0.94 mg L^-1, 18.11 mg L^-1 and 20.42 mg L^-1 respectively.