The pipeline inspection gauge (PIG) alert system provides a method and apparatus for effectively locating a pipeline inspection gauge (PIG) as it traverses a pipeline. The method and apparatus incorporates hollow, empty tubes spaced along the length of the pipeline. The tubes are provided with lower ends that extend into the pipeline. The tubes are closed at their lower ends and connectable to respective pressure detection devices or the like at their upper ends. When a PIG passes through the pipeline, it contacts the lower end of the tube that extends into the pipeline, causing the tube to break, and thus opening the interior of the tube to the pressurized flow of the product flowing in the pipeline. The change in pressure is registered by the pressure detection device to indicate the passage of the PIG.