The object-oriented paradigm is becoming increasingly popular, apparently as the result of expert opinion and anecdotal evidence, and not on the basis of sound empirical data. This questionnaire survey was undertaken as part of a programme of research to validate unsupported claims about the paradigm. The questionnaire follows our structured interviews of experienced object-oriented users with the intention to confirm the findings on a wider user group. It was posted to relevant electronic newsgroups and to members of an object-oriented (postal) mailing list. The survey received 167 responses to the electronic questionnaire and 119 responses (30% response rate) to the postal version. Results show that respondents are of the view that: (i) The object-oriented paradigm has advantages over other paradigms in terms of ease of analysis and design, programmer productivity, software reuse, and ease of maintenance. (ii) Inheritance can introduce difficulties when trying to understand object-oriented software. (iii) Missing design documentation and poor or inappropriate design are prevalent problems. (iv) maintenance causes degradation of object-oriented software, but less frequently than conventional software. (v) C++ has many deficiencies in comparison to other purer object-oriented languages.