PurposeThis paper examines the effects of non-professionals' involvements in real estate service provision on real estate agency practice in Ibadan Nigeria, in order to provide information that could enhance real estate agency practice in the country.Design/methodology/approachData were gathered through questionnaire administration on a total sample of 232 respondents comprising 82 estate surveyors and valuers, 100 non-professional estate agents and 25 real estate agency service consumers each from the respective clients of the two groups. A respondent-driven sampling (RDS) technique was adopted for data collection and was particularly useful in accessing non-professionals with characteristically less identifiable organizational structure. Data were analysed using mean scores on a Likert type scale while Spearman rank correlation was used to compare and establish if significant differences exist between the perceptions of clients of professionals and non-professionals on the services provided.FindingsThis study revealed that while the involvement of non-professionals in real estate agency practice deprives professionals of opportunities for legitimate earnings and is attributed to incidences of fraudulent transactions in the market, non-professionals often also serve as facilitators of transactions for the professionals. Hence, there seems to be a symbiotic relationship between the two groups and also a tacit validation of the involvement of the former by the latter.Originality/valueThis work contributes to and extends the body of knowledge on non-professionals' involvement in real estate professional practice by providing insights into the effects of activities of individuals who are not members of the real estate profession on real estate agency professional practice, particularly in the context of an emergent and less transparent market.