Goofs

Perry Mason's office is given as on the 9th floor of the fictional "Brent Building" in Los Angeles, and has a distinctive terrace outside (as does the next-door office in S.8 Ep. 30). However, establishing shots of the exterior use a photo of a plain-sided office building with no balconies or terraces on the 9th floor, or anywhere else.

In the episode "Case of the Crying Comedian", actress Sue Ane Langdon is seen sitting at the bar, then she comes down the stairs and moments later is seen sitting at the bar again.

Quite often during the run of the series, particularly in courtroom scenes, Perry Mason uses a variation of the word "infer" when he should be using a variation of the word "imply". The speaker "implies" while the listener "infers" (to draw a conclusion, as by reasoning).

In "Case of the Grinning Gorilla", you can see the flesh underneath the eyes of the actor portraying the gorilla, especially in the close-ups.

When Perry Mason picks up the folder from the judge's bench, the make-up on his hand and face can be clearly seen.

In the opening credits for seasons 2 and 3, the judge examines the contents of a folder and hands it to Perry. Perry looks inside the folder, smiles to himself, closes it, and presents it to Della and Paul, then to Burger and Tragg. The four of them only look at the front of the folder, yet they react as if they've seen the same intriguing information Perry noticed inside it.

It is not a subject of goofs when actors appear wearing glasses without lens. Some people do it for fashionable purposes and the power of lenses has nothing to do with the stories in this series.

During the opening scenes shown during Season 1 Paul and Della are shown in a normal courtroom sitting at the same table as Burger and Tragg. Defense and prosecutions sit at separate tables and not together.