General and social acceptance, condition, and rules for dog ownership in Iran are different from western countries. So, this phenomenon leads dissimilar fear and fear evoking stimuli in dogs. So, stress and fear‑related factors and dog's behavioral problems is not fully studied in Iran. Thus, the aim of the current study was to measuring fear‑related factors in dogs in Iran. In the first part of this study demographic information of the owners and dogs were collected using questionnaire from clinics and veterinary hospitals in Tehran. In the second part behavioral tests was done. Questionnaire data were recorded based on 4 items as neuroticism, fear caused by other dogs, fear caused by human and separation behavior. The social contact test was used to determine dog's experience for greeting, cooperation, and handling. According to the results, 69.3% of the dog owners were women and 30.7% men. 84.1% of the dogs were small breeds and 15.9% large‑breed dogs. 63.6% of the owner's complained for impact of laws and prohibitions on their dogs' access to outdoor. The score for greeting, cooperation and handling were 1.76 ± ± 0.93, 3.06 ± 1.25 and 2.44 ± 1.21, respectively. Mean score for neuroticism, fear caused by other dogs, fear caused by human and separation behavior were 29.69 ± 9.24, 14.75 ± 5.38, 9.84 ± 4.05 and 6.57 ± 3.05, respectively. Principal component analysis (PCA) revealed fear using neuroticism, fear caused by other dogs and human were 1st fear related factor while separation‑related behavior was the 2nd priority (P = 0.001). Small‑breed dogs had more separation behavior and fear caused by other dogs compared to the large‑breed dogs (P = 0.001). These findings suggested keeping the dogs indoor with limit access to a yard had negative impact on dog's behaviors. Legal restrictions have adverse effect on fear behavior in dogs. Determination of fear‑related factors might prove useful for dog's behavioral intervention in Iran.