This study aims to compare the concentrations of thiamine and histamine in the samples of 41 typical fluent speakers and 43 children who stutter in Jordan. Blood samples were collected for the determination of thiamine and histamine using high-performance liquid chromatography coupled to ultraviolet detector (HPLC-UV). The results revealed a significantly lower level of thiamine in the stuttering group (M = 29.9, SD = 15.6) compared with the control group (M = 38, SD = 19.3, p = 0.02), and a significantly higher level of histamine in the stuttering group (M = 20.5, SD = 6.5) compared with the control group (M = 9.4, SD = 7.5, p [less than or equal to] 0.00). The results also indicated a significant negative correlation between severity scores and the level of histamine. The findings of the current study may provide further supporting information about the relationship between childhood-onset stuttering and some biological markers such as thiamine and histamine.