Objectives: Aim of this study was to determine the current background exposure to pyrethroids in a collective of non-occupationally exposed persons by biological monitoring. By means of an additional questionnaire, parameters with a potential influence on the results and health effects of internal exposure were to be identified. Methods: Spontaneous urine specimens were collected from a random sample of n = 241 non-occupationally exposed persons (age: 19—75 years, median: 40 years; 49 % female). All urine specimens were assayed for the pyrethroid metabolites cis-/trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (cis-Cl2CA/trans-Cl2CA), cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane carboxylic acid (Br2CA) and 3-phenoxybenzoic acid (3-PBA). With the help of a standardized questionnaire, parameters potentially influencing the results such as sociodemographic data, domestic use of insecticides, and intake of fruits and vegetables were surveyed. In additional, the occurrence of symptoms which could be related to pyrethroid exposure was recorded. Results: In the study population the 95th percentiles of the metabolite concentrations were 0.13 μg/l (Br2CA), 0.17 μg/l (cis-Cl2CA), 0.36 μg/l (trans-Cl2CA) and 0.49 μg/l (3-PBA). Values exceeding the reference values published by the German Federal Environmental Agency (1 μg/l for cis-Cl2CA; 2 μg/l for trans-Cl2CA and 3-PBA, respectively) were found in two individuals and probably caused by the domestic application of insecticides. The analysis for the whole study group did not show any distinct relationships between the parameters surveyed by questionnaire and metabolite excretion. Also no associations between the occurrence of health effects which could be linked to pyrethroids and internal exposure were found. Conclusions: An individually increased uptake of pyrethroids can be detected readily by biomonitoring of urinary pyrethroid metabolites. Background exposure found in our study population seems to be influenced at best weakly by the parameters chosen for the survey. In a collective with background exposure, an elevated metabolite excretion does not seem to result in additional health complaints.