Due to the arid environment and excellent preservation on the north coast of Peru, the evidence obtained from macrobotanical remains are the primary sources of information on plant use. However, some plants, such as potatoes, are infrequently recovered as macrobotanicals because they are usually consumed in their entirety. For this reason, we have applied starch grain analyses to ceramic and lithic materials recovered from the Late Moche (AD 600–850) site of Wasi Huachuma (Je-65) in the lower Jequetepeque valley, Peru. The results of these analyses revealed the presence of potato (Solanum tuberosum) on the ceramics indicating the regular consumption of potato at this site during this period. Prior to this, physical evidence of potato had only been recovered from one other Moche context—dental calculus from Huaca Cao Viejo. This indicates that macrobotanical analyses alone are insufficient for uncovering the spectrum of foodstuffs utilized by the Moche. We argue for a more rigorous and consistent application of starch grain analysis, in order to obtain as much information as possible about past plant utilization, rather than relying on macrobotanical remains alone.