Grigor Taylor's first role after leaving the highly rated Matlock Police, Silent Number focuses on Dr Steve Hamilton, a doctor working for the New South Wales Health Department. Hamilton has chosen this path because he couldn't afford to start his own practice, and thought, even before he is seconded to the NSW Police as a police doctor, that this would be more rewarding than work as a GP. This situation causes some tension with his wife, who would rather he worked shorter hours for higher pay in private practice.

According to Don Storey in his Classic Australian Television, Silent Number suffered somewhat from the close attention of censors after early episodes were deemed too violent, which led to the Australian Broadcasting Control Board decreeing that all episodes must be submitted to them for assessment prior to screening. Storey also notes that Silent Number was screened in Melbourne opposite Matlock Police, which seriously damaged its ratings.

Nevertheless, Storey concludes that 'Silent Number was quite a good series. If you allow a certain suspension of disbelief for the premise - real police doctors rarely, if ever, get involved with criminal detection the way Steve Hamilton does - the only valid criticism that could be levelled against it is the "cheap" look that using videotape gives to the interior scenes.'

Moran, in his Guide to Australian TV Series, concurs with this assessment, noting that 'producer Roger Mirams and writer Ron McLean put their heads together to come up with a successful formula for the crime variation. They reasoned that because both medical and police series were popular, a series about a police doctor had to very popular. It wasn't. Again, though, the series is very watchable. Never profound, it does succeed as entertainment.'