Community animal health services (CAHS) have been promoted since the 1970s by aid organizations in low-income countries to improve the health of animals. They are also thought to improve directly the wealth and health or livelihood of their owners. We have systematically searched for observational studies of basic preventive and curative animal health services provided by a community animal health worker in communities in low-income countries. The objective was to summarize the available research on the effects of CAHS on indicators for household wealth and health. Studies for inclusion were assessed independently according to predefined eligibility criteria, the methodological quality of the studies examined, and data extracted. Fourteen studies of varying methodological quality met the inclusion criteria. The results were unclear in four studies, and in the remaining studies it was difficult to summarize the results because they reported different outcomes. However, the studies report that CAHS has a considerable potential for improving human health and wealth as well as animal health and productivity. Given the amount of money and time invested in this area, these observations need to be confirmed in the context of a well-designed study using standard pragmatic outcomes.