SUMMARY: Obesity is a severe health issue among companion dogs. It may seriously impair the quality of a dog's life predisposing to many other disease conditions. Incorrect assessment of the body condition (BC) of their pets by the dog owners has been identified as an obstacle which would prevent early intervention in canine obesity. This study was designed to assess the degree of agreement between the dog owner's perception of their pet's BC and the scientific assessment of body condition score (BCS). Eighty-two large pure bred dogs were included in the study. Scientific evaluation was performed using 1-5 BCS system proposed by Royal Canin™ (1-emmaciated, 2-thin, 3-ideal, 4-over weight, 5-obese). Following the scientific evaluation the owners were asked to assess their pet's BC using a grading system which included appropriate lay terms to describe the 1-5 scoring positions in the scientific method (1=very thin, 2=thin, 3=ideal, 4=fat, 5=very fat). In addition the knowledge of necessity of feeding adjustments and exercise, health risk of obesity and awareness of scientific BC evaluation methods were evaluated using a short questionnaire. Agreement between the owner's perception and scientific method was analyzed using