Occupational health research has generated a large body of evidence on psychosocial factors in the work environment that impact worker health. This knowledge on rather broad constructs however is not easily translatable into stress management approaches that are applicable in every-day working life. This project aims to set up an EMA (Ecological Momentary Assessment) measuring –within the natural working environment –subjects’ongoing and repeated work experiences, mental states, behaviors and activities, in connection with physiological signals. The project will build further upon an existing stress detection method using the Empatica wristband, an unobtrusive wearable device for physiological monitoring. A comprehensive protocol will be designed, including a smartphone application for self-report registrations, in addition to applications for automated registrations of work activities and events based on computer and smartphone usage. The complete protocol will cover three work weeks per subject and will be implemented in a field study including 100 office workers. Results from the project will advance existing knowledge in multiple ways, by allowing to improve existing and develop novel models for stress recognition based on physiological signals and technological registrations, and by allowing to investigate real-time relationships between daily fluctuating work experiences, mental states and micro-level events and activities inducing stress or engagement.