Nepenthes pitopangii was first discovered by British veterinarian, Jonathan Newman, during a birdwatching expedition through Lore Lindu National Park in September 2006. Newman came across the plant "[w]hile trying to get closer to a roosting Diabolical Nightjar [Eurostopodus diabolicus]", and initially thought it was N. eymae. The online publication of his trip report the following month brought the taxon to the attention of botanists. Further habitat photographs of N. pitopangii were posted online in January 2008 by Alfindra Primaldhi, who found the plant independently, having not seen Newman's report.
Nepenthes pitopangii is probablt closely related to N. Glabrata, a highland species also endemic to Sulawesi, but not recorded from the local area. While the stem, laminae, and lower pitchers of these species are very similar, the markedly different upper pitcher morphology means that they are unlikely to be confused. The aerial pitchers of N. glabrata are far more elongated than those of N. pitopangii and have well developed wings