The Multi-sensor dataset of environmental conditions in smart office consists of time series data acquired from sensors deployed in a smart office located in the ICAR CNR IoT laboratory in Rende ITALY for environmental monitoring. Various sensors were used including passive infrared, photocell light sensors, temperature and humidity, blind open controller, lamp controller, fan controller, gas controllers and others. The sensors record data from the environment, such as indoor movements, lamp and fan and blind control, CO and CO2 consumption, and others. Raw sensor data samples were collected continuously at a frequency of 60 Hz over a period of one month between 1 November 2022 and 27 November 2022. The dataset can be useful in the analysis of different tasks, including data-driven algorithms for comfort, people presence and intelligent appliance control. In particular, the research community might be interested in investigating information extraction and decision making applied to smart offices. Furthermore, by applying artificial intelligence (AI) algorithms on such data collected over long periods, it is possible to extract, e.g., patterns that reveal the user’s habits as well as detect environmental changes in the habits.