Socioeconomic status (SES) is known to have a considerable influence on the development of neuropsychological functions. In particular there is strong evidence for less efficient development of prefrontal-cortex-related functions in children raised in low-SES households. “Street children” are a common feature of low SES in many low- and middle-income countries, and some researchers have suggested that the unique life experiences of street children may drive their neurocognitive development. This study compares a group of 36 former street children in Quito, Ecuador with a control group of 26 never street-connected schoolchildren. All children were assessed with a range of neuropsychological tests. Although the street children group performed significantly below the level of the control group on all measures, they did not demonstrate a generalized lower ability. By controlling the effects of fluid intelligence it was found that there are relatively independent effects on visuospatial ability and executive planning ability. Furthermore, the executive function test scores in general are significantly less affected than the other cognitive functions and may be temporary effects caused by recent substance abuse within the street child sample. The findings generally support results from other countries suggesting that low SES is associated with negative effects on neuropsychological development. However, they also suggest that the local social and economic context, such as in the case of street children, might mitigate the harmful effects of low SES on the development of some executive functions.