The typical habitat of N. macrophylla is mossy montane forest along ridge tops, where the vegetation is dominated by Leptospermum and Rhododendron. Like most highland Nepenthes species, N. macrophylla experiences marked temperature fluctuations between day and night, from a noon maximum of around 30 °C to a nighttime minimum of 5 °C. Relative humidity is always high and in the late evening the summit of Mount Trusmadi is often shrouded in mist and clouds.