Primates are extracted from the wild for the pet trade across the world. In Madagascar, lemurs are kept as illegal pets and an understanding of lemur pet ownership at the national level is lacking. In 2013 and 2016, we undertook a national survey in 11 of Madagascar's 22 administrative regions (n = 28 towns) with 1,709 households. To our knowledge, this is the first national survey of the household ownership of pet primates in a country where they are endemic. In the 1.5 years prior to being surveyed, 8% ± 4% (towns as replicates) of respondents had seen a captive lemur while a further 0.7% ± 0.5% of respondents had owned one personally. We estimate that 33,428 ± 24,846 lemurs were kept in Malagasy households in the six months prior to our survey efforts, with 18,462 ± 12,963 of these pet lemurs estimated in urban household alone. Rates of lemur ownership did not differ by province but increased with the human population of a town and with the popularity of the town on Flickr (a proxy indicator for tourism). We found that the visibility of pet lemur ownership did not differ across the country, but it did increase with the size of the town and popularity with tourists. Areas with visible pet lemurs were not always the areas with the highest rates of pet lemur ownership, highlighting that many pet lemurs are hidden from the general public. Our study highlights the need for conservation programs to consider both the proportion of inhabitants that own pet lemurs and the total number of lemurs that are potentially being kept as pets in those towns. We close by noting that for some species, even just a small amount of localized live extraction for pet ownership could be enough to cause localized population extinctions over time. Moreover, an urgent response is needed to combat a recent and alarming rise in illegal exploitation of biodiversity across Madagascar.