Retail sales fell 11.8 percent in July compared to the same month last year, marking the fifth month of declines.
Official figures released on Friday showed the total value of retail sales came in at HK$29.1 billion in July.
The slump follows a 9.7 percent drop in June and an 11.4 percent decrease in May.
"The value of total retail sales declined further in July from a year earlier amid the continued impact of the change in consumption patterns and the strong Hong Kong dollar," a government spokesperson said in a statement.
"More outbound travels by residents during the summer holidays was also one of the factors."
Looking ahead, the government said challenges remain, but the authorities will continue to support small and medium-sized enterprises, including those in the retail industry.