PDD NOS stands for Pervasive Developmental Disorder, Not Otherwise Specified. It is actually part of the autism spectrum of disorders. But what does that mean? What does it look like? More importantly, if your child is diagnosed with PDD NOS, where do you go from there? If you are parenting or teaching a child with PDD NOS, find out exactly what it is and how to help a child with that diagnosis. Find out what PDD NOS means to you and your child.