Introduction. The aim of the study was to compare the effect of sous-vide treatment, cooking in boiling water, and steaming on changes in the colour, texture, and retention of selected bioactive compounds in root vegetables. Materials and methods. Carrots and parsley were subjected to sous-vide thermal treatment (SV) at 80 °C (SV 80) and 90 °C (SV 90), cooking in boiling water (B), and steaming (S) for 10, 20, and 30 minutes. Instrumental texture properties were assessed by texture profile analysis (TPA). The colour was measured with a colorimeter, and the content of total phenolic compounds and carotenoids was determined using the spectrophotometric method. Results and discussion. The hardness, ohesiveness, and chewiness of the analysed vegetables differed significantly depending on the method and duration of culinary processing. The highest hardness, cohesiveness, and chewiness values were demonstrated for the SV 80 variants. Most of the colour parameters of the vegetables differed statistically significantly depending on the method and duration of culinary processing. The lowest brightness (L*) was demonstrated for parsley B (20-min treatment), and the highest value of the parameter was noted for parsley samples SV 80 (10-min treatment). The highest values of parameter a*, which is the component of orange colour and determine the consumer attractiveness of carrots, were recorded in samples SV 80 and SV 90. Statistically significant differences were found in the b* value between the types of thermal treatment applied. The highest value of yellowness was noted for samples R (raw), whereas samples B (20-min treatment) had the lowest values of this parameter. In the case of carrots, the highest values of parameter b* were recorded in samples SV 90 (10-min treatment), and samples R exhibited the lowest yellowness value. The highest retention of phenolic compounds was detected in parsley B (20-min treatment) and carrots SV 90 (20-min treatment). The highest value of carotenoid retention was reported for parsley SV 90 (10-min treatment) and carrot SV 80 (10-min treatment). Conclusions. Compared to the boiled and steamed samples, sous-vide vegetables have higher hardness, cohesiveness, chewiness, and consumer-attractive colour. Carrots processed with this technique exhibit higher retention of carotenoids.