The need to determine adequate nitrogen (N) levels for potato crops in the Northwest during the growing season has required expensive petiole sample tests. The use of a SPAD Minolta chlorophyll meter by potato producers could reduce sampling costs and provide accurate in-season potato petiole N levels. The objective of this study is to compare the SPAD chlorophyll meter and petiole samples for accuracy in measuring N petiole levels for in-season N fertilization for potato crops. The study consisted of small plot studies in 2008, 2011, 2012, and on-farm studies in 2013. The small plot studies consisted of N treatments of 0, 56, 112, 168, 224, and 280 N kg ha-1 with three to four replications in a randomized complete block design were used to establish different N levels in the potato crop. Fertilizer was split applied with 56 kg N ha-1 applied at planting and remainder applied in June and July.  In 2013, the field scale trials had 20 sites within producer fields.  A single sample (of 20 petioles each) was taken from each field, which followed common practices for leaf petiole sampling).  Petiole nitrate (NO₃^-)samples, chlorophyll meter readings, and soil NO₃^- test were taken weekly for 8 weeks beginning in July through mid August.   Chlorophyll meter readings were compared to petiole NO₃^- and soil NO₃^- levels, which are current methods for determining in-season N fertilization need.  Potato plots were harvested by digging 3 meters of two adjacent rows and yields were determined based on total weight and weight by quality class.  Correlation between SPAD meter and petiole showed that a chlorophyll meter threshold of 47 or greater was equivalent to an 20,000 mg kg-1 petiole NO₃^- For mid-season, the petiole NO₃^- threshold drops to 15,000 mg kg-1 and the correlating chlorophyll reading was 41.  Similarly when the late season petiole NO₃^- threshold drops to 10,000 mg kg-1 the chlorophyll reading remains 41.  The similar chlorophyll meter reading between the mid and late season petiole NO₃^- levels is due to the lack of new vegetative growth and a lower NO₃^- concentration need in the petioles. Yield data did not correlate to N application, petiole chlorophyll meter readings probably due to large spatial variance and a large amount of residual N.  The data shows chlorophyll meter readings accurately indicate N responsiveness of the crop 80-100% of the time when compared to petiole samples. The 2013 field scale data will be needed to refine and support chlorophyll meter readings as a method to base in-season N fertilization decisions in potatoes.