This paper shows the prevalence of psychosocial risks for workers in the greenhouse construction industry in south-eastern Spain. Method: The assessment of the workers’ psychosocial risks was carried out through simple random sampling, which uses a questionnaire containing 13 variables characterizing the companies, 14 variables characterizing the workers, and 15 questions proposed by the Mini Psychosocial Factors (MPFs) risk assessment method. A descriptive analysis and multiple correspondence analysis were performed on the sample data. Results: Greenhouse construction businesses in south-eastern Spain can generally be classified as small companies with an average annual turnover below EUR 2.0 million (69.3%), an average of 22.8 workers with an average age of 39.84 years old, most of whom are married, with an average of 1.76 children. The prevalence of workers at high risk was 2.9%, while 45.1% were at medium-high risk. Of the 12 psychosocial factors assessed using the MPF method, 7 of them presented a high level of worker risk: Mobbing (3.2%), Relationships (1.6%), Recognition (1.6%), Autonomy (12.9%), Emotional (8.0%), Control (4.8%), and Demands (3.2%). Lastly, the variables were grouped into four clusters, showing that larger companies are correlated with a medium (workers over 40 years of age or less than 25 years of age) to high (workers under 25 years of age) risk level in several of the psychosocial factors assessed for workers who are Spanish nationals, while in smaller companies, the workers are usually middle aged (between 25 and 40 years old) and from Eastern Europe or Africa, presenting either a low or high level of risk depending on the psychosocial factors and tasks performed. Impact of the results: The study reveals a lack of prevention management regarding psychosocial risks. Therefore, it is necessary to carry out new prevention programmes that optimise the psychosocial conditions of the workers, involving the workers, employers, and other social agents.