Unusual fears have long been recognized as common in autism, but little research exists. In our sample of 1033 children with autism, unusual fears were reported by parents of 421 (41%) of the children, representing 92 different fears. Many additional children had common childhood fears (e.g., dogs, bugs, and the dark). More than half of children with unusual fears had fears of mechanical things, heights, and/or weather. The most common unusual fear was fear of toilets, and the most common category was fear of mechanical things. Amazingly, many of the fears reported in our sample were described in children with autism 70 years ago by Kanner, including fear of vacuum cleaners, elevators, mechanical toys, swings, and the wind. Children with autism perceive, experience, and react to the world differently than children without autism. What is tolerable for most children (e.g., clouds in the sky, a change in activity or routine, sensory input, or a performance request) might be terrifying, distressing, or infuriating for a child with autism. It is critical to assess for unusual and common fears in children with autism because they are present in the majority of these children, they further impair functioning, and effective treatment is available. (Contains 4 tables.)