We tested the effects of different preservatives and temperatures on the yield of spider and scorpion DNA useable for PCR amplification. Our experiment was designed to simulate conditions in the field and laboratory over a six-week time period, testing the preservatives RNAlater^®, propylene glycol, and various ethanol concentrations. Three replicates of each preservation treatment were stored at five different temperature treatments; –80°C, –20°C, 2–4°C, 19–24°C, and 40°C. DNA was extracted and quality was assessed by electrophoresis on mini-gels, and by PCR amplification of high copy mitochondrial DNA fragments (cytochrome oxidase subunit I) and low copy nuclear DNA fragments (actin). Results show that RNAlater^® and propylene glycol are significantly better than the other preservatives for high quality DNA preservation and that tissue is best stored at –80°C or –20°C. Storage in 95% ethanol is appropriate if specimens are stored at –20°C or –80°C. We believe our results can help guide biologists in choosing preservatives and temperatures for DNA-based research on arachnids, other arthropods and invertebrates in general.