Objectives Pre-exposure prophylaxis (PrEP) users are screened bi-annual for sexually transmitted infections (STIs). A novel device, called the Colli-Pee, collects first-void urine in a standardised way and the collector tube can be easily delivered by regular post to a certified laboratory. The aim of the study was a one-to-one comparison between the STI test results obtained with the urine collected in the clinic, versus urine collected at home in a real-life setting by Men who have Sex with Men (MSM) in Belgium. The user-friendliness and acceptability of the Colli-Pee device by the users was also evaluated. Design A single-site nested substudy in a prospective PrEP demonstration project (Be-PrEP-ared) among MSM in Belgium. Participants A total of 473 home-based samples from 213 MSM were received with a mean age of 38.5 years. Interventions Participants were requested to collect a urine sample at home using the Colli-Pee device and to send it to the laboratory via regular mail. Primary and secondary outcome measures The presence of Chlamydia trachomatis (CT) , Neisseria gonorrhoeae (NG) , Mycoplasma genitalium (MG) and Trichomonas vaginalis (TV) was determined using molecular amplification assays. Agreement between test results of samples collected at the clinic and collected at home were evaluated using Cohen’s kappa statistic. Results: TV was not detected. A very good to almost perfect agreement was found for CT, NG and MG of κ=0.75, 0.87 and 0.85, respectively. Using the Colli-Pee device only one low positive CT and two MG infections were missed, however, three additional CT, two NG and six MG infections were detected. Conclusions The Colli-Pee device is a feasible and convenient way to collect urine at home for STI testing. This may be particularly relevant for populations that need frequent STI testing, such as PrEP users and patients who prefer home-sampling. Trial registration number NCT02552914; Pre-results .