The aims of the study were to investigate frequencies of low unstimulated whole saliva (UWS) levels and low serum ferritin (S-f) levels among individuals with active dental caries (ADC) and dental caries inactive (DCI) individuals and to compare the relationship between UWS and S-f levels. In this descriptive study, 48 ADC patients and 48 DCI individuals were compared. The two groups were matched regarding age and sex (30 females and 18 males in each group, age range 15-40 years). In the ADC group, 32 individuals (67%) had low (< or = 0.20 ml/min) UWS levels compared with 13 individuals (27%) in the DCI group. This difference was statistically significant (P < 0.001). The mean values of UWS were significantly lower in the ADC group compared to the DCI group (mean ml/min +/- SD) 0.20 +/- 0.13 and 0.33 +/- 0.24, respectively (P = 0.002). There were significant differences for females but not for males when comparing frequencies of low UWS levels (P < 0.001) and mean UWS levels (P = 0.002). There was no difference in S-f levels between the two groups. Neither was any correlation between UWS and S-f found. In conclusion, the significant negative relationship found between UWS and ADC indicates that a suppressed defense for dental caries activity could play a more important role in ADC than previously presumed, especially among females. The absence of a correlation between UWS and S-f might indicate that saliva secretion will not be stimulated by iron supplementation.