Effects of welding parameters on the characterization and mechanical properties of steel 37 weldments were investigated on a single V-shaped groove weld joint. These parameters are; type of electrode, welding current, welding speed, and type of used arc welding and plate thickness. Radiography, metallography and mechanical testing were carried out for the steel 37 weldments. Results indicated that as the heat input increased, the welding current and plate thickness increased but the welding speed decreased. The grains of the base metal, heat affected zoon (HAZ), root and cap were changed in size and phases in these locations. Radiography showed that no defects were found. The average hardness values were 173 HB at base metal, 175 HB at the HAZ, 180 HB at the cap and 133 HB at the root, respectively. Yield strength, ultimate tensile strength and elongation of the welded steel 37 were in the range between 374 and 425 MPa, between 542 and 606 MPa and in the range between 34.6 and 37.5 %, respectively. Such values tend to increase with increasing the current and heat input and decreasing the plate thickness. The chemical and mechanical properties of the welded electrodes proved to influence the efficiency of the welding process. The best welding results were obtained with current 75 A at the root, 130 A at the cap and welding speed of 1.3 mm/s in the root and 2 mm/s in the cap.