A school gymnasium was accidentally flooded by the fire-suppression sprinkler system. The surface water was removed immediately and, after 10 days, a professional firm engaged to dry the environment. Twenty five days after the flooding, the school decided to evaluate whether there was any mold growth in the gymnasium. The inspector used two approaches, traditional air samples or a DNA-based analysis of dust samples. Thirty five-minute air samples (for total of 75 L of air each sample) were collected with Air-O-Cell™ (AOC) cassettes and the mold structures (MS) were quantified by microscopy. These samples were compared to two identical outdoor air samples. As an alternative, two dust samples were collected and quantified by mold specific quantitative PCR (MSQPCR). Comparisons of indoor to outdoor mold concentrations in air samples were inconclusive, but applying MSQPCR to the investigation of this water-damaged environment provided a more reliable and useful answer to the extent of mold contamination than did the spore trap analysis.