The quality of user manual translation is one of the factors that can spell out success or failure for producers expanding their business internationally, yet this area of translation has not been researched to a great extent. By discovering the most common types of errors in user manual translation and how severely they affect the meaning of the target text, the thesis aspires to shed some light on this neglected area of technical translation and make a step towards raising awareness among producers about the importance of hiring professional translators. To achieve this, a corpus of ten Croatian user manuals for small household appliances translated into English is compiled. The errors are annotated using the Multidimensional Quality Metrics (MQM) framework and a quantitative and qualitative results analysis is presented. Saturated with errors and demonstrating a clear lack of revision, the analyzed translations are sub-par. Errors related to grammar, spelling and typography account for well over a half of all identified errors, but it is the less occurring errors related to accurate and consistent use of terminology that have a major effect on the meaning of the translated user manuals and result in confusing or even misleading the user. Errors related to accuracy, such as mistranslations, omissions and additions, have proven to affect the text in a critical way, reducing the usability of the product and compromising consumer safety. Judging from the researched corpus, the importance of good user manual translation seems to be overlooked in Croatia, but before any definitive conclusions can be drawn, further research into the topic is required.