The aim of the present study was to investigate how the presence or absence of a verbal label of an odor affects its familiarity or hedonicity. In addition, we wanted to examine how the participants' age or sex influences the effect of odor-label presentation on familiarity and hedonicity. A total of 12 odorants from the "Sniffin' Sticks" odor identification test were presented to 133 participants (50 men and 83 women) with an age range from 5 to 74 y. Familiarity and hedonicity of the odorants were assessed by using a 6-point scoring scale both before and after participants received the odor label. In 5 and 8 odorants, respectively, odor familiarity and hedonicity were significantly different between before and after participants had received the label. Moreover, the relationship between the odor familiarity and hedonicity was different between the situation when participants had an odor label or not. Specifically, in odors that had been perceived as relatively pleasant without a label (orange, cinnamon, lemon, and banana) the correlation between hedonicity and familiarity decreased after the label had been presented. This was the other way around for odors that had been rated as relatively unpleasant when presented without a label (shoe leather, coffee, clove, and fish). Moreover, the odor label effects on the relationship between odor familiarity and hedonicity seemed to be influenced by the participants' age and sex. In conclusion, our results indicate that the relationship between odor familiarity and hedonicity is not always positive, and is influenced by the presence of an odor label and other variables, including the participants' sex, age, and expectations.