Abstract Background Postpartum sepsis is one of the leading causes of maternal mortality and morbidity in developing countries. This formative research elicits local terms used for postpartum illnesses and symptoms of postpartum sepsis with the aim of improving postpartum diagnosis and management in Pakistan. Methods We conducted 34 in-depth interviews with recently delivered women (RDW), traditional birth attendants (TBAs), healthcare providers and family members of RDW from rural Sindh to explore local Sindhi terms used to describe postpartum sepsis and related symptoms. During interviews, all participants were asked to orally free list common symptoms of postpartum illnesses; those who were aware of the concept were asked to free list possible symptoms of postpartum sepsis. The responses were recorded by the interviewer. Free listing data were analyzed for frequency and salience. Results Most participants, including TBAs, were not familiar with the concept of postpartum sepsis as a distinct disease or of a local term denoting the concept. Almost all could identify and report symptoms related to postpartum sepsis in the local language. Only physicians were able to recognize the term postpartum sepsis and related symptoms. Multiple local terms were used for a particular symptom; still others were used to denote gradations of severity. ‘Bukhar’ (fever) was the most commonly named symptom although it was often considered a normal part of puerperium. Many postpartum illnesses were related to the highly non-specific local term ‘kamzori’ (weakness). Conclusions Better awareness about local terminology used in rural areas related to postpartum sepsis could improve communication, care-seeking patterns, diagnosis and management.