This presentation addresses MEMS failure modes that are either unexpected or judged insignificant on a macroscale. Although MEMS devices can fail from typical "macro" effects such as overload, fatigue, or corrosion, in many instances these phenomena are accentuated once one addresses micron sized devices. Examples cited include stress corrosion of silicon, creep of membrane and thin film structures, electrostatic accumulation, shock resistance, and strength reduction due to processing effects. Possible countermeasures are included with each example, and suggestions are provided for additional investigation on MEMS reliability.