Almost 1,400 people across north and north-east Scotland had to wait six weeks or more before their cancer was diagnosed.
More than 550 people had to wait at least six weeks to get their condition identified by NHS Grampian medics in September.
New government figures reveal an 11% rise in north-east residents having to wait a month and a half or more to find out what their illness is.
In August, 495 patients saw their diagnosis take six weeks or more, rising to 554 in September.
Despite the rise, the recent figures are significantly lower than at the same point last year, when 908 people were waiting six weeks or more.
NHS Highland enjoyed a slight fall of around 2% in the number of patients waiting a month and a half or more – but 820 patients experienced a delay in September, according to the government figures.
A spokeswoman for NHS Grampian said: “We face a number of challenges in achieving the 62 day target consistently across all cancer types.
“We have a number of improvement processes underway to attempt to streamline the relevant patient pathways which we anticipate will lead to sustained improvement but these will take time.
“The overall numbers are fairly low and small variations in actual patient numbers have a significant effect on the percentage performance.
“However, we recognise this will be a very anxious time for patients and their relatives and would wish to reassure all patients that they are closely monitored to ensure that they receive appropriate treatment as quickly as possible.”
A spokeswoman for NHS Highland added: “Access to diagnostic services is a concern for us.
“We have revised contracts which allow us to access offsite radiology reporting services.
“Taking advantage of technological advances that have been implemented in the recent past, in addition process improvement work is being progressed within the Radiology service. Radiology is a service that is under significant pressure due to a lack of numbers of available Consultants to support recruitment nationally.
“There have also been significant challenges within endoscopy services however plans are now in place to reduce the number of patients waiting.”