To determine the relationship of gingival pigmentation of different passive smoker age groups (both genders) with active household smokers in Erbil city/Iraq. Passive smoking is also called ETS (Environmental tobacco smoke) is the result of spontaneous cigarette burning, and contrarily, the result of the side-stream of cigarette smoke, as well as the smoke exhaled by active smokers. ETS produces numerous side effects including oral cavity of people who do not smoke like oral mucosal pigmentation, which is fundamentally, cigarette smoking affecting smile and esthetics. Health personnel should clearly present the data concerning the adverse results of smoking, in addition to the dangers to exposure to environmental tobacco smoke. A total of 400 patients attending different dental clinics in Erbil city, participated in the study, 170 passive smokers case group, and 230 non-smoker control group (age 18-70 years) (112 male, 58 females for case group) and (128 male, 102 females for control group) were included in the study sample. All the participants were assessed for gingival pigmentation and were medically free of any systematic disease. The additive number and percentage of control group with the total of pigmentation-lack (male 101, 25.25%) (female 95, 23.75%) (total 196, 49%) was higher than case group (male 85, 21.25%) (female 49, 12.25%) (total 134, 33.5%) with highly significant difference at P=0.000 level. For gingival pigmentation case group in its specific details 36 (male 28, 7%)(female 8, 2%) was higher in number and percentage than control group 34 (male 27, 6.75%) (female 7, 1.75%) without significant difference at P 0.1322 but for total case group (36, 9%) was higher than total control (34, 8.5%) with statistically significant difference at P 0.0322. Concerning severity of gingival pigmentation grade 0: Total control group number and percentage 196 (49%) was higher than total case number and percentage 133 (33.25%) with highly statistically significant difference between them P=0.0013 level. For Grade 1: There was no statical significant difference between total control and case groups for gingival pigmentation at P 0.5 level. For Grade 2: Total case group number and percentage 15 (3.75%) was higher than total control group 12 (3%) with statistical significant difference at P=0.06 level concerning distribution of gingival pigmentation according to age relating factor higher number and percentage were seen at age (30-39 years) for case group more than control group with highly significant difference at P 0.0012, followed by age (40-49 years) case group was higher in number and percentage more than control group with highly significant difference at P=0.000 level, while for age (18-29 years) control group number and percentage was higher than case group with significant difference at P=0.029 level followed by group 50 years control group number and percentage was higher than case group with highly significant difference at P=0.000 level.