The Broadcasting Standards Authority says it is increasingly addressing the difficult problem of how reality television deals with participants' rights to privacy and fair treatment.
The authority's annual report shows it received 195 complaints compared with 250 the year before and the decisions it made fell by 74.
The report says the decrease in decisions came after a record high number of decisions in 2011, which was partly down to multiple complaints about the same programme.
BSA chief executive Susan Freeman-Green says when the system works well, the number of complaints will fall over time.
She says a downward trend in the number of upheld decisions and orders could relate to the BSA's more robust analysis of freedom of expression.
The report highlights that reality TV is becoming a growth area for complaints, throwing up questions of fairness, privacy, informed participation and informed consent.