Good afternoon. My name is Terri and I will be your conference operator today. At this time, I would like to welcome everyone to the Trimble's First Quarter 2018 earnings call. All lines have been placed on mute to prevent any background noise. After the speakers' remarks, there will be a question-and-answer session. (Operator Instructions)
Thank you. I would now like to turn the call over to Mr. Michael Leyba, Director of Investor Relations.
Thanks Terri. Good afternoon everyone and thanks for joining us on the call. I am here today with Steve Berglund, our CEO and Rob Painter, our CFO. I would like to point out that our earnings release and the slide presentation supplementing today's call are available on our website at www.trimble.com as well as within the webcast and we will be referring to the presentation today.
Turning to slide two of the presentation, I would like to remind you that the forward-looking statements made in today's call and the subsequent question-and-answer period are subject to risks and uncertainties.
Trimble's actual results may differ materially from those currently anticipated due to a number of factors detailed in the company's Form 10-K and 10-Q or other documents filed with the Securities and Exchange Commission. The non-GAAP measures that we discuss in today's call are fully reconciled to GAAP measures in the tables from our press release.
With that, please turn to slide three for an agenda of the call today. First, Steve will start with an overview of the quarter. After that, Rob will take us through the remainder of the slides, including an in-depth review of the quarter, our guidance and then we will go to Q&A.
With that, please turn to slide four and I will turn the call over to Steve.
Good afternoon. The narrative for the first quarter is consistent in most ways with that of the fourth quarter and is notable for its strength across both businesses and regions. Reported revenue growth was over 20% with organic revenue growth continuing to track in double digits.
Reported non-GAAP operating margins improved by more than a point versus the first quarter of last year and the improvement was even stronger after allowing for acquisition effects. We continue to operate with the most positive outlook we have had in over 10 years. Every segment and every significant region is growing and all are anticipated to continue to grow during 2018.
We are also experiencing renewed higher growth in segments in which recent growth has been relatively modest, such as (inaudible). We do remain observant of potential negative macro effects and volatility, most particularly in the realm of US trade policy. While we are taking advantage of simultaneous vertical and regional market upswings, we continue to focus on and invest in the major multiyear secular trends that are specific to our markets. Our singular focus is on achieving leadership in the digitization of targeted mature industries and providing transformative benefits to those markets. We believe we have, in