This work was undertaken to determine the efficacy of the milk spray-drying process for killing Mycobacterium avium subsp. paratuberculosis (Map). In the absence of pilot plant equipment with the necessary safety containment facilities a tripartite approach was adopted. Firstly, using M. smegmatis as a surrogate for Map and pilot plant equipment the organism was subjected to evaporation heat treatments which are a precursor to the spray-drying stage of milk powder production. Mycobacterium smegmatis did not survive evaporation treatments ranging from 75ºC for 15s to 85ºC for 4 min. Secondly, M. smegmatis was found to have a significantly higher (P<0.05) D value (D₆₃8.71 min) than Map (D₆₃6.78 min) at 63ºC using milk concentrate as the heating menstruum. Thirdly, milk powder from 3 plants within Northern Ireland was surveyed over a year period for Map using PCR assays based on the IS900 insertion element and culture. Although 9.5% (18/190) samples were positive by PCR no culture positives were obtained. This work provides credence for considering spray-drying as one strategy for dealing with milk suspected of containing viable Map and destined for human consumption.