Proper application of HACCP in catering services involves monitoring decisive critical points. The purpose of this study was to assess food temperatures and surface hygiene control in two catering services in Navarra (Spain) at two different time periods: the first one after implementation of the HACCP system and the second period, after the initial supervision through audits and a specific training session regarding temperatures of products and hygienic conditions of surfaces and equipment because the majority of detected nonconformities were related to these parameters. The recorded temperatures of 650 cooked food products within the first period showed that only 65.1% of the hot dishes had a temperature higher than 65 °C, in accordance with Spanish legislation, and 12.9% of them showed a risky holding temperature (<55 °C). However, the percentage of noncomplying dishes was reduced by a half after the training session (p < 0.001). Since the significant differences observed in recorded temperatures were related to the type of meal (with or without sauces) and the type of cooking procedure, a lower safe criterion for the retention of hot dishes was suggested if the temperature is continuously maintained over 55 °C until serving. With regard to cleaning and disinfection, 18.3% of the 600 analyzed surfaces did not meet the established cleaning criterion (≤100 CFU/25 cm2) in the first period, while in the second period this percentage was reduced to 13.6% in both catering businesses (p = 0.021). The dirtiest surfaces were equipment such as cutting boards and meat slicing machines (>26%) compared to utensils for distribution (12.0%). As the impact of dirty surfaces on the hygienic quality of a finished product will depend on which step was being taken during dish elaboration when equipment or utensil was used, it is suggested that more restrictive limits be established regarding utensils and equipment that are in direct contact with the finished product (≤1 CFU/cm2). Results of the study demonstrate that a specific training session on these items has improved the temperature control of prepared meals and the effectiveness of cleaning and disinfection, essentials for guaranteeing the hygienic quality of prepared foods.