Background:
Public health interventions are always composed of several interconnected actions and hence they are popularly referred to as 'complex'. The domain of complexity lacks clarity and the conceptual framework needs to be simplified and strengthened as, to date, most of the issues/concepts relating to this domain remain unexplored. This paper investigates the perception of complexity among people working in the area of public health.

Objectives:
To investigate the perception of complexity among people working in the area of public health.

Methods:
We adopted a qualitative study design and conducted unstructured interviews/dialogues/focus group discussions among people working in the public health domain on their perception of complexity. The process was audio-recorded and the interpretations were summarized. A perception mapping was carried out to consolidate the responses.

Results:
This paper provides an outlook on how people perceive the complexity in public health interventions. Participants perceived complexity in a diverse manner, which was evident from the variety of responses obtained. The discussions led to the creation of eight broad themes: complexity is a serious issue for public health evidence consolidation; complexity lies in the target population; intervention contributes to complexity; contextual factors add on to complexity; outcomes of a public health intervention study are complex; leading contributor for complexity - population, intervention, context or outcome; consequences of complexity; strategies for handling complexity.

Conclusions:
Complexity in public health interventions is a concept that is still not well understood, but used very often and very loosely.